Am J Vet Res 1995;56:825.
VETERINARY
Pharmacists Helping Vets and Pets
Our specialty service should not be viewed as competition with local veterinarians; rather, compounding allows veterinarians to broaden their prescribing abilities and to offer [dosage] forms that are patient-specific in strength and formulation. Therefore, the goal of compounding for the veterinary patient is to enhance the veterinarian’s ability to treat patients in a more effective and efficient manner.
“Compounding can make medicating animals easier if the pharmacist prepares flavored chews that animals accept readily. For example, tranquilizing a feral cat with a liver-flavored chew eliminates the possibility of over- or underdosing. If a chew contains 10mg acepromazine and the dose fails to gain a response, a second flavored chew can be given to the animal. Furthermore, the amount of medication incorporated into the chews, capsules, [topical or transdermal], or liquid preparations can be formulated to the specific request of the veterinarian, thereby eliminating the need to cut-up tablets and divide the contents of commercially prepared capsules… As manufacturers decide that certain products are no longer economically rewarding to market, the list of commercially prepared veterinary medication becomes smaller. At present, the armamentarium of medications available for animals is less than perfect. Cherry-flavored amoxicillin or orange-flavored cephalexin may not be [appealing to a cat or monkey]…”
Veterinary Forum October 2002, (pp. 62-65)
Our compounding pharmacy can prepare:
- Flavored medication
- Medicine in ideal size, strength, and dosage form
- Unavailable medications
- Combinations to improve compliance
- Novel devices and delivery systems
Compounding is actually a means to an end. We work together with veterinarians and their clients and patients to solve medication problems by compounding specialized medications that meet the unique needs of each animal – pets, exotics, horses, or zoo animals. Let us know how we can help you and the animals in your care
Transdermal Medications
Have you ever thought about applying a transdermal preparation to the inside of an animal’s ear or another hairless area as an alternate route of systemic administration? It’s quick and easy, and many medications are compatible with transdermal bases. Transdermal delivery is particularly useful for animals who should not be stressed due to cardiovascular or hypertensive illness. Also, it is appreciated by owners who no longer have to deal with an animal who resists being medicated, and the resulting scratches! We can also prepare topical medications for application at the site of inflammation or infection.Advantages of Transdermal Dosage FormsVarious alternative dosage forms permit medication to be absorbed via non-oral routes to meet an animal’s specific needs. Although the parenteral and rectal routes are traditional alternatives to oral administration, transdermal absorption offers many advantages.For example:
Anti-Infective Therapy
Mycobacterial Infections in Dogs and Cats
Behavioral Medicine
Transdermal Treatment for Aggressive Cat
Cardiology / Hypertension
Compounding For Feline Hypertension
Therapies for feline hypertension have not often been systematically evaluated. Therapies that have been employed and reported include diuretics (furosemide and spironolactone), angiotensin-converting enzyme inhibitors (ACE-I; captopril, enalapril, lisinopril, and benazepril), beta-blockers (propranolol and atenolol), and calcium channel blockers (diltiazem and amlodipine). Littman retrospectively evaluated 24 cats with chronic renal failure (CRF) and found that the most effective antihypertensive therapy was the combination of a beta-blocker and an ACE-I and that there was a poor response to furosemide. Jensen prospectively studied 12 similarly affected cats and found that the response to an ACE-I or beta-blocker alone was poor. A North Carolina State University study retrospectively found amlodipine to lower blood pressure ≥ 20% in 30 of 32 hypertensive cats with 28 of 32 becoming normotensive. Diltiazem and beta-blockers alone or with ACE-I also lowered blood pressure in the majority of cats so treated. The literature and clinical experience would, nevertheless, lead one to appropriately conclude that amlodipine is the single best agent for the management of feline systemic hypertension, and that the adjunct therapies mentioned above may be added if indicated.
To reduce stress to the cardiovascular system of the feline patient and to preserve the owner-pet bond, palatable, non-invasive therapy is mandatory for treatment of feline hypertension. Amlodipine is dosed at 0.3mg – 0.625mg orally once to twice daily, and has also been shown to be effective when applied transdermally at approximately twice the effective oral dose. Amlodipine is only FDA approved for human use and is available in tablet sizes far too large to afford safe and effective therapy in cats. Our compounding pharmacists can compound amlodipine into oral suspensions, capsules, treats, and powders to sprinkle on food, as well as into transdermal gels for application to the pinnae. Diltiazem may also be utilized to lower feline blood pressure and is available in several human-approved dosage forms that are, again, far too large for use in cats. Diltiazem controlled-delivery (Cardizem CD®) is the only dosage form of diltiazem that demonstrates pharmacokinetics to support once daily dosing in cats. Available as a capsule containing a 40/60 mixture of immediate release and sustained release beads of diltiazem, compounding pharmacists can reformulate these capsules into 45mg (total) doses for once daily administration to cats. Diltiazem has not been sufficiently evaluated to determine whether or not transdermal administration is effective; however, there are many anecdotal reports of efficacy. Atenolol may be useful in reducing heart rate in hypertensive cats and is dosed empirically at 6.25mg – 12.5mg per cat orally once daily. Again, our compounding pharmacists can provide palatable dosage forms of atenolol that are voluntarily accepted by feline patients. For feline patients requiring multiple therapies, we can also provide combination therapies in a single dosage form. For example, we can compound a single capsule or treat that contains amlodipine, diltiazem and atenolol, further reducing the stress to both patient and owner. We invite veterinarians wishing to explore palatable and non-invasive therapies for cats with hypertension to consult with our compounding pharmacists.
J Vet Intern Med. 1994 Mar-Apr 1994;8(2):79-86.
Spontaneous systemic hypertension in 24 cats.
Littman MP.
Click here to access the PubMed abstract of this article.
Am J Vet Res. May 1997;58(5):535-540.
Plasma renin activity and angiotensin I and aldosterone concentrations in cats with hypertension associated with chronic renal disease.
Jensen J, Henik RA, Brownfield M, Armstrong J.
Click here to access the PubMed abstract of this article.
J Am Vet Med Assoc. Sep 2000;217(5):695-702.
Ocular lesions associated with systemic hypertension in cats: 69 cases (1985-1998).
Maggio F, DeFrancesco TC, Atkins CE, Pizzirani S, Gilger BC, Davidson MG.
Click here to access the PubMed abstract of this article.
J Am Anim Hosp Assoc. 2007 May-Jun 2007;43(3):149-156.
Treatment of feline hypertension with transdermal amlodipine: a pilot study.
Helms SR.
Click here to access the PubMed abstract of this article.
Low Dose Anti-platelet Therapies for Feline Arterial Thromboembolism (FATE)Feline hypertrophic cardiomyopathy (HCM) is the most common form of heart disease in cats and is characterized by concentric thickening of the left ventricle. The clinical consequences of ventricular hypertrophy include arrhythmias, congestive heart failure, and feline aortic thromboembolism (FATE). FATE carries an extremely poor prognosis with a 66% mortality rate. The formation of aortic clots in FATE leads to paralysis, severe leg pain and, often, death. There is no cure for HCM; hypertrophy of the heart wall is irreversible. Therapies demonstrating benefit to HCM patients include beta-blockers, diuretics, ACE inhibitors, and antiplatelet drugs. Because systemic warfarin therapy is associated with a high occurrence of hemorrhagic events, aspirin has historically been utilized as the primary oral antiplatelet therapy to prevent FATE in cats with HCM. It was initially dosed at 81mg every 72 hours as this was the smallest commercially available dosage form of aspirin. A study in 2003 revolutionized low dose aspirin therapy in cats through utilization of a compounded 5mg aspirin capsule administered orally every 72 hours. Results of this study indicated that the same degree of antiplatelet activity was achieved but the inhibition of endothelial production of prostacyclin (PGI), an antagonist to platelet aggregation and vasoconstriction, is not affected with the 5mg dose as is seen with the 81mg dose. This study also demonstrated a lower incidence of gastrointestinal adverse effects with the 5mg dose when compared to the 81mg dose of aspirin.Clopidogrel (Plavix™) has been shown to be more effective than aspirin in preventing myocardial infarction, stroke and peripheral vascular events in humans. Clopidogrel has recently been evaluated in cats and has been shown to significantly inhibit multiple platelet functions. Investigators concluded that a low dose of 18.75mg of clopidogrel (1/4 of a commercially available 75mg tablet) given orally once daily was safe and effective anti-platelet therapy for cats. Investigators also commented that a considerably lower compounded dose of clopidogrel may prove to be as effective, safer, and considerably less expensive than quartering the commercially available tablets and recommended that studies be performed with lower doses of clopidogrel as were done with aspirin in 2003. Some veterinary teaching hospitals are utilizing doses of 6mg and 7mg clopidogrel orally once daily in combination with low dose aspirin therapy although the efficacy of these therapeutic regimens have not been evaluated. The multi-centric Feline Arterial Thromboembolism – Clopidogrel vs. Aspirin Trial (FAT-CAT) initiated at Purdue University College of Veterinary Medicine has been accepting FATE cats for enrollment for the last two years to determine if there is clinical superiority of either agent when prophylaxing against recurrence of FATE. Initial results show a significant (41.6%) reduction of FATE recurrence in one of the two treatment groups; however, study coordinators will not unblind the treatment arms to investigators until the full enrollment of 30 cats per treatment group is achieved. Clinicians interested in learning more about the FAT-CAT study should visit
Dermatologics
Alternative Therapies for Atopy Dogs with atopic dermatitis (AD) often have concurrent allergies and are prone to relapsing skin and ear infections, which significantly contribute to their discomfort level. Much research has been done in recent years to identify effective and safe alternative treatments. Percutaneous absorption of allergens may be the most relevant route of exposure in dogs. Topical therapy may reduce the amount of allergen absorption through the skin. Several preparations, including glucocorticoids and anesthetics, can be used to reduce pruritus and provide analgesia.Cyclosporine , misoprostol, pentoxifylline, and various antihistamines have been effective.
Endocrinology
Low Dose Trilostane for Canine Cushing’s Disease
Cushing’s Disease (hyperadrenocorticism) is a common condition in older dogs, often mistaken for the aging process itself. Dogs get pot bellies, lose hair, drink and eat excessively, urinate in the house, and make owners begin to prematurely consider euthanasia. Yet, Cushing’s disease is treatable and that treatment can result in a longer, more comfortable life for the dog and its owner.Trilostane is the most promising FDA-approved treatment for canine Cushing’s disease. Current FDA approved labeling for trilostane (Vetoryl™) lists the recommended dose at 3-6mg/kg body weight orally once daily, and Vetoryl™ capsules are available in strengths of 10mg, 30mg and 60mg. Several studies conducted prior to US-approval of trilostane referenced effective doses ranging from 6-12mg/kg orally per day. After noting that many dogs treated with trilostane at the labeled dose demonstrated symptoms of hypoadrenocorticism (Addison’s Disease), clinical endocrinologists at the University of California Davis College of Veterinary Medicine evaluated the safety and efficacy of lower doses of trilostane. Investigators in this trial administered trilostane to dogs diagnosed with Cushing’s disease at doses ranging from 0.5-2.5mg/kg orally every 12 hours and evaluated dogs for therapeutic progress at 3 different treatment intervals over a total treatment period of 8-16 weeks. After 1 to 2 weeks, mean trilostane dosage was 1.4 mg/kg (0.64 mg/lb) every 12 hours (n = 22 dogs; good response [resolution of signs], 8; poor response, 14). Four to 8 weeks later, mean dosage was 1.8 mg/kg (0.82 mg/lb) every 12 or 8 hours (n = 21 and 1 dogs, respectively; good response, 15; poor response, 5; 2 dogs were ill). Eight to 16 weeks after the second reevaluation, remaining dogs had good responses (mean dosages, 1.9 mg/kg [0.86 mg/lb], q 12 h [n = 13 dogs] and 1.3 mg/kg [0.59 mg/lb], q 8 h [n =3]).Since many dogs that develop Cushing’s disease are smaller breed dogs weighing less than 9kg (e.g. terriers and poodles), the commercially available capsules (10mg, 30mg and 60mg) are too large for appropriate therapy. As a result of the UC-Davis study, many veterinarians are requesting compounding pharmacists to compound smaller doses of trilostane as capsules or oral suspensions. On September 11, 2009, the Center for Veterinary Medicine division of the Food and Drug Administration issued a statement to veterinarians and pharmacists that “trilostane can only be legally compounded by using FDA-approved VETORYL™ as the starting material”, and that “…trilostane should not be imported from other countries or compounded from (the) pure (chemical)”. As Vetoryl™ is only available for sale to licensed veterinarians in the US, and use of the pure chemical to compound trilostane will not be tolerated by FDA, veterinarians and pharmacists are advised to collaborate to ensure availability of safe and legal compounded dosage forms of trilostane for dogs requiring lower doses than are commercially available.
Otitis
Therapy for Chronic Canine Otitis
Treatment errors, over and under treatment, or inappropriate use of antimicrobial medication can result in a chronically diseased ear. The key to successful management of chronic canine otitis is early intervention, identifying a cause of the condition, and employing specific and appropriate therapy.Ears with highly proliferative, chronic disease require deep cleaning and flushing before any topical therapy can be expected to help resolve the condition. Should a myringotomy be performed, the contents of the middle ear can be aspirated as soon as rupture occurs, and the middle ear can be flushed with normal saline or Tris-EDTA using a feline, open-tipped urinary catheter. “Just before the animal wakes, Tris-EDTA and a topical antimicrobial solution should be instilled and a parenteral prednisolone administered.””The pathogens isolated most frequently from chronic external and middle-ear infections include Staphylococcus intermedius, Malassezia pachydermatis, Pseudomonas species, Proteus species, Escherichia coli, and enterococcus. Selection of both systemic and topical antimicrobial medication is based on cytologic evaluation and culture and sensitivity results. Systemic antibiotics are mandatory… Treatment should continue until the infection is resolved (a minimum of 4 weeks). It is not uncommon for treatment of otitis media to continue uninterrupted for 8 to 12 weeks.”Patricia D. White, DVM, MS of Atlanta Veterinary Skin & Allergy Clinic suggests that several compounded preparations may be appropriate.
Pain Management
Gabapentin for Pain Management
Although the mechanism of action remains largely unknown, gabapentin is a useful adjunct in management of chronic pain in small animals. Recommended doses vary considerably. Anticonvulsant dosages range from 10-30mg/kg q8hrs (dogs) and q8-12hrs (cats). However, analgesic dosages for chronic pain management are substantially lower ranging from 3mg-10mg/kg orally every 8-12hrs, although dosages as high as 30mg/kg orally every 8 hours have been employed. Peak blood levels occur in about 2 hours and the most commonly reported side effect is drowsiness.Gabapentin is approved for use in humans and is available in various capsule and tablet strengths as well as a 50mg/ml oral solution. The oral solution, however, contains 300mg/ml xylitol as a sweetener making it inappropriate for use in dogs. The lowest strength solid dosage form available is a 100mg capsule which pet owners cannot reliably split into smaller doses. Small dogs and cats must receive compounded doses of gabapentin to achieve an appropriate dose and to avoid xylitol exposure. Our compounding pharmacists are able to prepare a gabapentin 100mg/ml xylitol-free oral suspension that can be flavored according to patient preference and is stable for 3 months in the refrigerator. Gabapentin capsules, treats and powders to mix with food may also be compounded. A clinical trial is currently underway at NC State College of Veterinary Medicine to determine safety and efficacy of compounded gabapentin transdermal gel for cats.
Transmucosal Buprenorphine: More is Better For Dogs and Horses
The pharmacokinetic profile of a buccally-administered (transmucosal) dose of buprenorphine to cats is almost identical to that of intravenously administered buprenorphine. The unusually alkaline salivary pH of cats prevents ionization of buprenorphine, allowing it to diffuse into systemic circulation in a non-ionized form. This discovery greatly facilitated outpatient feline pain relief, allowing owners to administer this drug to cats at home, without the need for hospitalization or injection. Because the duration of analgesia from buprenorphine (4-12hrs) is longer than that provided by other opiates, buprenorphine is frequently used for provision of non-invasive, intermediate to long-term analgesia in cats. It is typically administered at doses of 10-30mcg/kg applied to the oral mucosa (inside the cheek pouch) every 8 hours for up to 5 days (many cats experience anorexia after 5 days of therapy with buprenorphine). The commercially available 300mcg/ml solution for injection (Buprenex) works well for buccal administration with most cats receiving volumes of approximately 0.066ml/kg (e.g. 0.33ml for the average 5kg cat).Buccal absorption of buprenorphine has also been examined in dogs at approximately the same dose (20 mcg/kg) utilized in cats. Absorption was low at this dose, but a dose of 120 mcg/kg administered transmucosally to dogs produced drug concentrations equivalent to an intravenous dose of 20 mcg/kg. Dogs have a relatively more acidic salivary pH than cats, resulting in more ionization of buprenorphine, reducing the amount of drug available for diffusion across membranes. At doses of 120mcg/kg, a 25kg dog would require 3000mcg or 10ml of the commercially available buprenorphine solution for injection. A canine patient would likely swallow a large portion of 10ml administered buccally, and since the oral absorption of buprenorphine is extremely low, analgesic effect would not be achieved. Recent work at NC State University (unpublished) also demonstrates that buccal buprenorphine provides effective analgesia in horses when administered at doses of 6.6 mcg/kg (e.g. 11ml of the commercially available injection for a 500kg horse). Again, a significant portion of this dose is likely to be swallowed by an equine patient, precluding a full analgesic effect.For dogs and horses, a more concentrated solution of buprenorphine is greatly desirable for transmucosal use. Compounded solutions of buprenorphine from 3-6mg/ml would allow for buccal administration of volumes of less than 1ml for both dogs and horses. Our compounding pharmacy can prepare concentrated solutions of buprenorphine for transmucosal use in dogs and horses.
Poisoning / Toxicosis
Xylitol Poisoning in Dogs
Compounding pharmacists are now receiving requests from veterinarians to compound oral medications for dogs and cats in vehicles that are known to be free of xylitol. Xylitol is an artificial sweetener commonly used to sweeten human medications, gums, mouthwashes and candies, and while not toxic to humans, can be quite toxic to dogs. Xylitol is not absorbed from the gastrointestinal tract of humans, but is easily absorbed in dogs. Once in the bloodstream, xylitol acts like glucose, stimulating insulin secretion, which causes life-threatening hypoglycemia. Profound hypoglycemia can last for 1-2 hours following xylitol ingestion, and has frequently resulted in death. Many commercially available drugs labeled for humans, such as gabapentin oral suspension, contain xylitol as an inactive ingredient, and all human medications used in dogs should be scrutinized for xylitol content. Compounding pharmacists can play a valuable role for veterinarians and veterinary patients by providing xylitol-free suspensions of medications and by educating clients to avoid all xylitol-containing foods in their pets. It is not currently known if xylitol is toxic in cats, but for the present, xylitol must also be assumed to be toxic to cats. For more information, search “xylitol” at
Apomorphine to Stimulate Vomiting
Veterinary Compounding Resources — Continued
← Back to Veterinary ResourcesSeizure Control
Potassium Bromide for Seizures
by Mollyann Holland, D.V.M., Oklahoma City, OK
Diplomate, American College of Veterinary Internal Medicine
Potassium bromide is frequently helpful in treating refractory seizures in animals. Because potassium bromide is excreted renally, it may also be preferable for use in animals that have developed hepatotoxicity while on other anticonvulsants. My compounding pharmacist prepares this as a liver flavored solution, which can easily be administered to dogs. I feel that it is important to inform my animal owners that potassium bromide solution is compounded from a reagent grade chemical, and is not a commercially available “drug.”
KBr is dosed on a weight basis. Maintenance doses range from 20-100 mg/kg body weight/day, and can be given as a single or divided dose. I usually dose at 30-40mg/kg/day as a single dose with food. Due to its long half-life, KBr can take up to four months to reach steady state; therefore, a loading dose may be required if therapeutic blood levels must be reached quickly. The loading dose is 400-600 mg/kg body weight and is administered orally over 30 to 60 minutes to avoid vomiting. A loading dose is not necessary if it is possible to keep the animal on other medications (as in a case of emerging hepatotoxicity) until levels of bromide are therapeutic (0.5-1.5 mg/ml), when the other anticonvulsant can be tapered off.
Potassium Bromide Chewable “Treats” for Seizure Control
Contributed by Steve Toney, R.Ph., Erin King, C.Ph.T. and Pam Woodin, D.V.M.
Case Report: 5 y.o. male Golden Retriever with seizure disorder. The owners called our compounding pharmacy to see what we could do as they were having difficulty administering medications to their dog. We suggested medicated canine treats that we have compounded many times with a 100% success rate. The veterinarian was consulted and we prepared potassium bromide (KBr) 150 mg treats coated with liver and beef flavored powder. The owner administers two treats two times daily, and the dog now loves to take his medicine!
Note: Chewable treats can be compounded to contain a variety of medications and flavored for the specific breed or pet. This dosage form has high patient acceptance and a low risk of owner misdosing.
Potassium bromide (KBr) can be also compounded as an oral solution which is easy to flavor and convenient for use as a loading dose. However, the risk of owner misdosing is greater than with a chewie or capsule.
Phenobarbital: Problems and Solutions
While phenobarbital is often used in veterinary medicine to treat seizure disorders, there are several concerns with its use:
- there are no commercially available veterinary approved products
- phenobarbital tablets for human use are small, hard, and unscored, making them difficult to divide for individualized dosing
- phenobarbital elixir has a high alcohol content, which is problematic for cats or any species when chronically administered
- phenobarbital induces CYP450 hepatic enzymes which can result in substantial drug interactions with oral anticoagulants, steroids, antibiotics, beta-blockers, theophylline, etc.
- phenobarbital is contraindicated in dogs with hepatic disease
When you wish to prescribe phenobarbital, please be aware that our compounding pharmacy can prepare an alcohol-free, appropriately flavored oral suspension, which is highly bio-available and very easy to use when administering a loading dose or when a flexible dose is needed. Once the maintenance dose is established, the dosage form can be switched to a capsule (with a lower risk of misdosing by the owner) or a flavored chewable medicated “treat”, with the added benefit of high patient acceptance.
Urology
Feline Painful Bladder Syndrome (FPBS)
Oral amitriptyline is the mainstay for medical treatment of FPBS and provides analgesia and anticholinergic action through many mechanisms. Chronic therapy with amitriptyline in controlling FPBS may be more effective than using it for short term in acute episodes. Dosing is typically empiric and ranges from 2.5mg per cat to 12.5mg per cat, with a typical starting dose being 5mg orally once daily in the evenings. Dose may be increased upwards until a calming effect is observed and resolution of clinical signs occurs. If there is no response after 4 months, the drug should be gradually tapered and discontinued over several weeks.
Adverse effects of amitriptyline include hepatotoxicity and hepatic enzymes should be evaluated before initiation of therapy as well as at 1 month, 2 months and 6 months post administration. Other adverse effects include sedation and possibly urinary retention through anticholinergic mechanisms. The most undesirable property of amitriptyline hydrochloride is its extremely bitter taste. Administration of split tablets or tablets crushed in food has resulted in episodes of profuse salivation and head shaking in cats. Since FPBS is a syndrome precipitated by stress, administration of amitriptyline without masking the taste can actually worsen FPBS symptoms. Compounding pharmacists have many techniques to assist in masking the taste of amitriptyline.
Vet Clin North Am Small Anim Pract. 2005 Jan;35(1):147-70, vii.
Recent concepts in feline lower urinary tract disease.
Click here to access the PubMed abstract of this article.
Feline Urethral Obstruction
“Blocked” cats are one of the most common life-threatening emergencies presented to veterinary clinics. Urethral obstruction (caused by calculi, urethral plug, or urethral spasm) is a completely curable condition following which most treated cats go on to live happy, normal lives. Cats suffering from urethral obstruction will usually exhibit signs of pollakiuria, dysuria, stranguria, hematuria, vocalizing while straining to urinate, bilateral inguinal alopecia (sometimes with excoriation) and a recent history of peruria (house soiling). Accurate triage of the etiology of feline urethral obstruction is paramount as inability to excrete urine can lead to bladder rupture and life-threatening hyperkalemia resulting in cardiac arrhythmias and death. Complete workup of blocked cats includes a physical exam, EKG, clinical laboratory assessment of hematology and electrolytes, and hydration status assessment. Initial triage involves establishment of an intravenous catheter, analgesia, treatment of electrolyte abnormalities, and resolution of obstruction. Once the obstruction is removed, the bladder is irrigated with saline until the effluent appears to be free of blood, clots or other debris. A urinary catheter is usually left in place for at least 48 hours to ensure continued ability to void urine.
Re-obstruction due to urethral spasm is a common occurrence following removal of calculi or urethral plugs, so treatment with an anti-spasmodic is usually warranted. The proximal (pre-prostatic) portion of the feline urethra is primarily controlled by alpha receptor mediated smooth muscle, while the distal (post-prostatic and penile) portion is primarily controlled by striated muscle. The alpha-1 antagonists, phenoxybenzamine (2.5mg per cat orally every 8-12 hrs) and prazosin (0.25mg per cat orally every 12 hours), are very useful in relieving urethral obstruction. Dosing with phenoxybenzamine and prazosin should be carefully controlled as sedation and profound hypotension can result from overdosage. While extremely effective for relief of urethral spasm in cats, neither phenoxybenzamine nor prazosin are commercially available in dosage forms that are suitable for accurate administration of very small, very specific doses. Fortunately, our compounding pharmacist can formulate both drugs in patient-specific doses. For prevention of recurrence, cats with obstruction from urethral plugs or urethroliths should be changed to canned diets to decrease urine concentration and supersaturation, and plenty of fresh water should be offered to encourage adequate urine dilution. The survival rate for cats discharged after successful treatment of obstructive uropathy is currently 90%, and the availability of patient-specific doses of the alpha-1 antagonists prazosin and phenoxybenzamine will ensure that this survival rate continues to increase.
J Am Vet Med Assoc 199(2): 211-6.
Clinical evaluation of cats with lower urinary tract disease.
Kruger, J. M., C. A. Osborne, et al.
Click here to access the PubMed abstract of this article.
J Vet Emerg Crit Care 13(4): 227-233.
Characterization of the clinical characteristics, electrolytes, acid-base, and renal parameters in male cats with urethral obstruction.
Lee, J. A. and K. J. Drobatz.
Click here to access more information.
J Amer Vet Med Assoc 221(4): 502-505
Evaluation of trends in frequency of urethrostomy for treatment of urethral obstruction in cats.
Lekcharoensuk, C., C. Osborne, et al.
Click here to access the PubMed abstract of this article.
Treating Feline Urethral Spasm
Feline lower urinary tract disease (FLUTD) is a spectrum of different diseases that present with a common set of clinical signs regardless of the underlying cause. Cats with FLUTD, usually present with signs of dysuria (difficult urination), pollakiuria (increased frequency of urination), hematuria, agitation or vocalization (crying or howling) when unable to urinate due to urethral obstruction. Obstructive FLUTD can be a serious condition and may lead to post-renal azotemia, renal azotemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and acidemia. These combined metabolic and renal disruptions can rapidly prove fatal. Therefore, cats presenting with lower urinary tract obstruction require immediate treatment. Acute renal failure and death can result in 1-3 day if urinary tract obstruction is left untreated.Urethral spasm may occur in many cases of FLUTD, regardless of the underlying cause. Spasms may be initiated by local pain or inflammation, and may affect the smooth and/or skeletal muscle of the urethra. It may therefore be beneficial to give drugs to counter both smooth and skeletal muscle effects. While these drugs are rarely associated with side effects in young cats, the risk of concurrent renal or cardiac disease should be assessed before these drugs are given to older cats. Smooth muscle anti-spasmodics include prazosin 0.25-1.0 mg/cat PO q8-12h, and phenoxybenzamine 0.5-1.0 mg/kg PO q12h–give for 5 days before evaluating efficiency. The most commonly used skeletal muscle anti-spasmodic is dantrolene given at 0.5-2.0 mg/kg PO q12h.There have been only a limited number of studies into the use of anti-spasmodic drugs in the relief of urethral spasm in cats; however, prazosin, phenoxybenzamine and dantrolene have been shown to be most beneficial. Unfortunately, all of these drugs are commercially available in capsule forms that cannot be safely and accurately administered to cats. Because prazosin and phenoxybenzamine are smooth muscle alpha adrenergic antagonists, profound hypotension is a potential adverse effect. For this reason, these drugs have a very narrow therapeutic index, and veterinary clinicians prefer to only use these drugs in carefully titrated doses. Our compounding pharmacy is able to provide these valuable anti-spasmodic drugs in palatable, appropriately-sized dosage forms and optimal individualized strengths. While none of these drugs are stable for long periods of time in liquid dosage forms, we can compound capsules containing one or more of the anti-spasmodics individualized for a specific patient, or provide as medicated treats. Due to the delayed onset of transdermal medications, this dosage form is not appropriate for use in treating this potentially life-threatening condition.
AJVR 1995 Jul;56(7):919-23.
Urethral pressure response to smooth and skeletal muscle relaxants in anesthetized, adult male cats with naturally acquired urethral obstruction.
Click here to access the PubMed abstract of this article.
AJVR 1992 Jul;53(7):1161-5.
Urethral pressure response to alpha-adrenergic agonist and antagonist drugs in anesthetized healthy male cats.
Click here to access the PubMed abstract of this article.
AJVR 1996 Oct;57(10):1497-500.
Effects of acepromazine maleate and phenoxybenzamine on urethral pressure profiles of anesthetized, healthy, sexually intact male cats.
Click here to access the PubMed abstract of this article.
Treatment for Urinary Incontinence
Hormonal Therapy:
Diethylstilbestrol (DES) has been used to treat estrogen responsive incontinence in spayed female dogs. The use of DES is contraindicated in cats as daily use has resulted in pancreatic, hepatic, and cardiac lesions.
Dose for dogs:
Initially 0.1-1.0 mg PO daily for 3-5 days, followed by maintenance therapy of approximately 1 mg PO per week. Some animals may require much higher initial dosages to obtain a response. DES can be given PO to female dogs at 0.1-0.3 mg/kg/day for 7-10 days, followed by a similar dose once weekly. Dogs should be maintained at the lowest possible dose because bone marrow suppression can develop when diethylstilbestrol is given in high doses. 1,4
When therapy is chronic or high dosages are used, packed cell volumes, white blood cell counts, and platelet counts should be done at least monthly. Liver function tests should be done at baseline, one month after therapy, and repeated 2 months after cessation of therapy if abnormal.
Clients should be informed to contact the veterinarian if signs and symptoms of lethargy, diarrhea, vomiting, abnormal discharge from vulva, excessive water consumption and urination or abnormal bleeding occur. DES is not for human consumption and should be dispensed only in child-resistant containers and stored in a secure location.1
DES is not currently commercially available; however, the medication can be prepared by a compounding pharmacy.
Adrenergic Agonists:
Phenylpropanolamine (PPA) is a weak alphaagonist that increases urethral sphincter tone and produces closure of the bladder neck, and is used to treat urethral sphincter hypotonus and resulting incontinence in dogs and cats.
Dose1:
Dogs: 1.1 mg/kg PO every 8 hours Cats: 12.5mg PO every 8 hours
The effect is short-lived, and the dose needs to be titrated to effect. “Dogs that are older at the onset of clinical signs (median 5 years) and those with a longer period from the time of ovariohysterectomy to the onset of urinary incontinence (median 2.5 years) respond best. PPA is preferred to ephedrine because side effects are less severe; ephedrine has greater cardiovascular side effects and it tends to lose effectiveness over time.”2 In a multicenter, blinded, placebo-controlled trial, 50 dogs that presented with clinical signs consistent with urinary sphincter mechanism incontinence were treated for 28 days with either PPA (1 mg/kg three times daily) or placebo. At day 28, 85.7 per cent of PPA-treated cases had no episodes of unconscious urination compared with 33.3 per cent of placebo-treated cases.3
Potential side effects include restlessness, irritability, hypertension and anorexia. Numerous drug interactions exist.
In November 2000, human PPA preparations were removed from the market due to reports of serious side effects in humans. PPA continues to be available as a pure chemical for veterinary use only.
- Veterinary Drug Handbook, 3rd edition, Donald C. Plumb, ed. pp.193-5, and 508-9
- Handbook of Veterinary Drugs, 2nd edition, pp. 277-8
- J Small Anim Pract. 2002 Nov;43(11):493-6
Evaluation of phenylpropanolamine in the treatment of urethral sphincter mechanism incompetence in the bitch.
Click here to access the PubMed abstract of this article.
Cancer Chemother Pharmacol 1992;29:214-218
Phase I trial of piroxicam in 62 dogs bearing naturally occurring tumors.
Click here to access the PubMed abstract of this article.
J Vet Intern Med 1994;8:273-278
Piroxicam therapy in 34 dogs with transitional cell carcinoma of the urinary bladder.
Click here to access the PubMed abstract of this article.
Cancer Chemother Pharmacol 2000;46:221-226
Cisplatin versus cisplatin combined with piroxicam in a canine model of human invasive urinary bladder cancer.
Click here to access the PubMed abstract of this article.
Urologic Oncology 2000;5:47-59
Naturally-occurring canine transitional cell carcinoma of the urinary bladder: A relevant model of human invasive bladder cancer.
Citrate Salts as Alkalinizing Agents
Citrate salts are a source of bicarbonate, but are much more palatable than bicarbonate preparations. “They are used as urinary alkalinizers when an alkaline urine is desirable and in the management of chronic metabolic acidosis accompanied with conditions such as renal tubular acidosis or chronic renal insufficiency. Potassium citrate alone has been used for the prevention of calcium oxalate uroliths. The citrate can complex with calcium thereby decreasing urinary concentrations of calcium oxalate… When urine is alkalinized by citrate solutions, excretion of certain drugs (e.g. quinidine, amphetamines, ephedrine, etc.) is decreased, and excretion of weakly acidic drugs (e.g. salicylates) is increased. The solubility of ciprofloxacin and enrofloxacin is decreased in an alkaline environment [and patients] should be monitored for signs of crystalluria.” (Plumb’s Veterinary Drug Handbook, 2nd ed.) In combination with potassium citrate preparations, these agents may lead to severe increases in serum potassium levels: NSAIDs, ACE-inhibitors, cyclosporine, digitalis, heparin and others.Fludrocortisone AcetateFludrocortisone is a long-acting corticosteroid with potent mineralocorticoid and moderate glucocorticoid activity. It is used in small animal medicine for the treatment of adrenocortical insufficiency, where it promotes sodium retention and urinary potassium secretion. It is commercially available only as the human product, a tablet containing 0.1 mg fludrocortisone acetate. The maintenance therapy for animals (particularly dogs) can require administration of multiple tablets for each daily dose. Therefore, it may be more convenient for owner and animal to administer fludrocortisone acetate as a flavored suspension, or single flavored solid dosage form.Aluminum Hydroxide for HyperphosphatemiaFor dogs and cats, aluminum hydroxide is initially dosed at 30 – 90 mg/kg orally one to three times daily. A preparation that can be mixed with food may be preferred as it is more easily dispersed throughout ingesta. Dosage must be individualized, and serum phosphate levels should be evaluated at 10-14 days to determine optimum dosage.
Veterinary Drug Handbook, 3rd edition, Donald C. Plumb, editor. pp. 48-49
Calcitriol for Chronic Renal Failure
Submitted by Shirley Russman, D.V.M.
Our protocol for treating chronic renal failure includes a special diet, adequate hydration, potassium supplementation, stomach acid control and calcitriol therapy to control phosphorus levels. Calcitriol (a vitamin D3 metabolite) may also be used to prevent or reverse secondary hyperparathyroidism in dogs and cats with chronic renal failure.
Calcitriol is dosed in nanograms. Commercially available products are for humans, and the dose is much too high for dogs or cats (for example, the capsule contains 250 nanograms or 0.25 micrograms). Our compounding pharmacist has been able to prepare any capsule (8 nanograms and up) or liquid (i.e. 4 nanograms/0.25ml) necessary to meet our needs. We have used this compounded remedy over one hundred times and have found it to be very successful in lowering phosphorus levels in our patients with chronic renal failure. Serum calcium levels should be monitored as hypercalcemia is a possible consequence of calcitriol administration.
Editor’s Note:
Calcitriol “has a rapid onset of action (1-4 days) and a short half-life (4-6 hours). Oral calcitriol is administered to patients after initial stabilization with fluid therapy, dietary protein and phosphorus restriction, the use of intestinal phosphate binders and H-2 blockers as needed. Serum phosphorus should be less than 6 mg/dL (1.9 mmol/liter) before initiating calcitriol.
“Hypercalcemia usually only occurs if calcitriol is used in conjunction with intestinal phosphate binders, especially calcium carbonate… Long-term use of phenytoin and the barbiturates may interfere with the action of the drug, necessitating higher doses of calcitriol… Thiazide diuretics may enhance the effects of calcitriol predisposing to hypercalcemia. Calcitriol-induced hypercalcemia may antagonize the antiarrhythmic effects of calcium channel-blocking agents.”
Handbook of Veterinary Drugs, 2nd edition, pp. 105-106
Wound Care
Would you like a topical medication that is difficult for an animal to lick off or that will adhere to a mucosal surface?
You can prescribe a medicated “polyox bandage” or “mucosal bandage”. When moistened, this medicated preparation will adhere to a wound or mucosal surface, thereby providing a protective barrier and increasing the contact between the medication and the affected area.Wound and Incision Care – Prevent LickingA common problem encountered by veterinarians and animal owners is preventing an animal from licking an incision or licking medication from the area to which it has been applied. In addition to injury to the wound, pharmacists and veterinarians must consider the consequences of internal consumption of an external preparation. To prevent an animal from licking, a medication can be compounded to contain an extremely bitter substance. Choices include diphenhydramine, quinine, or the non-therapeutic ingredient sucrose octaacetate. Sucrose octaacetate can be added at 1% to 5% to any topical dosage form and the bitterness usually prevents the animal from repeated licking of the area of application. Another way to protect a medicated area from licking is to incorporate the needed medication into CAP (Cellulose Acetate Hydrogen Phthlate) solution. Since CAP solution does not dissolve in an acidic pH, the animal’s saliva does not remove it from the skin. CAP solution can also be sprayed directly onto a wound or over stitches to protect them.
Phenytoin/Lidocaine Poly-Ox Bandage Used to Treat Leg Wound
Problem: Twenty-four hours after an automobile accident, an eight-month old female pit bull presented with a leg injury that appeared as if it would have difficulty healing. The dog had been hit by an automobile, which had scraped a hole in the right front leg. The wound, which extended from the elbow to the carpus, was approximately 3/4″ to 1″ wide.Treatment: The tissue of the leg was stabilized using tension-relieving sutures. Because the veterinarian had prior successful experiences with other cases involving wound care, she requested we compound a topical preparation consisting of 2% phenytoin and 2% lidocaine in a methylcellulose/polyoxyethylene (poly-ox) bandage for the dog. The animal underwent hydrotherapy twice daily and the compounded medication was applied just before bandaging was secured.Outcome: The wound was completely healed after 2 months of therapy and the animal has full use of her leg with no visible ill effects. According to the veterinarian, the animal healed much quicker than usual due to the increased contact time of the medications and she was satisfied with the treatment process.We have also used this compound with the same positive success on a degloved feline after its paw had been caught in a fence overnight.Reference:
Randy S. Carr, R.Ph., FIACP & Pamela Doskey, D.V.M.
Therapy for Severe Chemical Burns
by Barbara Espe, D.V.M., North Dakota
In April 1998, I was called to euthanize a 1 1/2 year old female miniature schnauzer that had been burned with hot water from the bath tub and washed in Woolite? 3-4 weeks earlier. The full thickness burns involved about 80% of the skin on the dorsal trunk from neck to tail and elbows to midthigh. The owners were using aloe vera to treat the burns and she had a severe infection, was emaciated (5 lb.) and had not eaten for one week. Since she had survived so long without treatment, I had the owners sign ownership over to me and I contacted the Central Dakota Humane Society. They agreed to take on this project despite the many hours of labor and the potential cost. The dog was immediately given an analgesic and antibiotics.
I literally stopped at the pharmacy with the dog so the compounding pharmacist could see what we were up against. At the pharmacist’s suggestion, a Poly-Ox bandage containing phenytoin base 2% and misoprostol 0.002% was compounded and applied in a layered manner. Telfa? pads were used to cover the wound, and a T-shirt was put on to protect the bandages. The dog started eating canned food that night and in several days she was eating four large cans of food daily. In addition to the Poly-Ox bandage, she remained on Cefadrops? and Rimadyl?. She seemed to be uncomfortable and analgesics did not appear to control her pain. The powder was returned to the pharmacy and lidocaine 2% was added. Although this helped somewhat, the dog was becoming non-compliant at the time of her dressing changes. The compound was again modified to contain bupivacaine 0.2% to obtain an extended analgesic effect. This was a significant improvement and therapy continued for several months. As healing occurred, the dog began to experience itching in the regranulated skin and wound areas. Diphenhydramine was given orally along with the Rimadyl? and we began rubbing her stretched skin with Emu oil to keep it moist. Shortly thereafter, the dog “became a schnauzer again.” Her activity level has increased greatly and we anticipate a complete recovery.
When I began treating this dog, I thought that skin grafting would be necessary. Due to the success of this therapy, no grafting will be needed. However, I don’t expect hair regrowth and the epithelium will remain scarred and easily bruised.
Equine
Equine Canker
Equine canker is a chronic, hyperproliferative, suppurative, pyogranulomatous pododermatitis of the frog, bars, and sole and, in severe cases, the adjacent hoof wall. The lesion appears grossly as soft, whitish, cauliflower-like proliferations associated with a foul-smelling caseous exudate. Canker is commonly reported in draft horses and usually affects the rear feet, however, it has been reported in many other equine breeds and has been known to affect all four feet. Episodes of canker are known to be seasonal and the majority of cases present during July through December. Canker is associated with wet or unhygienic (or both) stall conditions and is caused by opportunistic infections by treponeme spirochetes. A recent investigation1 detected 19 different phylotypes of treponemes present in canker-infected equine hoof tissue, but did not determine antimicrobial susceptibility for the organisms found. Treatment of canker has always been extremely difficult, and mortality due to foot loss has been high. In the 2004 Proceedings of the American Association of Equine Practitioners, Dr. Stephen O’Grady presented a compounded topical therapy which has subsequently become the therapy of choice in treating equine canker.2 He details treatment and outcome for a series of 56 cases of equine canker from 1998-2004 that all experienced consistent and predictable efficacy from this treatment. The therapy consists of a topical dressing of benzoyl peroxide, acetone, and metronidazole, covered by an elastomer putty protective layer and is changed daily. Treatment was continued for weeks to months or until the hoof tissue sufficiently recornified. The therapy described by Dr. O’Grady is not commercially available, but this compound, containing highly concentrated solutions of benzoyl peroxide and acetone, can be obtained through our compounding pharmacist.
J Vet Med Sci. 2010 Feb;72(2):235-9.
Detection of treponemes in canker lesions of horses by 16S rRNA clonal sequencing analysis.
Kyaw Kyaw Moe, Takahisa Yano; Atsutoshi Kuwano; Satomi Sasaki; Naoaki Misawa.
Click here to access the PubMed abstract of this article.
Proceedings of the American Association of Equine Practitioners, 2004.
How to treat equine canker.
O’Grady S, Madison J.
Transmucosal Buprenorphine: More is Better For Dogs and Horses
The pharmacokinetic profile of a buccally-administered (transmucosal) dose of buprenorphine to cats is almost identical to that of intravenously administered buprenorphine. The unusually alkaline salivary pH of cats prevents ionization of buprenorphine, allowing it to diffuse into systemic circulation in a non-ionized form. This discovery greatly facilitated outpatient feline pain relief, allowing owners to administer this drug to cats at home, without the need for hospitalization or injection. Because the duration of analgesia from buprenorphine (4-12hrs) is longer than that provided by other opiates, buprenorphine is frequently used for provision of non-invasive, intermediate to long-term analgesia in cats. It is typically administered at doses of 10-30mcg/kg applied to the oral mucosa (inside the cheek pouch) every 8 hours for up to 5 days (many cats experience anorexia after 5 days of therapy with buprenorphine). The commercially available 300mcg/ml solution for injection (Buprenex) works well for buccal administration with most cats receiving volumes of approximately 0.066ml/kg (e.g. 0.33ml for the average 5kg cat).Buccal absorption of buprenorphine has also been examined in dogs at approximately the same dose (20mcg/kg) utilized in cats. Absorption was low at this dose, but a dose of 120 mcg/kg administered transmucosally to dogs produced drug concentrations equivalent to an intravenous dose of 20 mcg/kg. Dogs have a relatively more acidic salivary pH than cats, resulting in more ionization of buprenorphine, reducing the amount of drug available for diffusion across membranes. At doses of 120mcg/kg, a 25kg dog would require 3000mcg or 10ml of the commercially available buprenorphine solution for injection. A canine patient would likely swallow a large portion of 10ml administered buccally, and since the oral absorption of buprenorphine is extremely low, analgesic effect would not be achieved. Recent work at NC State University (unpublished) also demonstrates that buccal buprenorphine provides effective analgesia in horses when administered at doses of 6.6mcg/kg (e.g. 11ml of the commercially available injection for a 500kg horse). Again, a significant portion of this dose is likely to be swallowed by an equine patient, precluding a full analgesic effect.For dogs and horses, a more concentrated solution of buprenorphine is greatly desirable for transmucosal use. Compounded solutions of buprenorphine from 3-6mg/ml would allow for buccal administration of volumes of less than 1ml for both dogs and horses. Our compounding pharmacy can prepare concentrated solutions of buprenorphine for transmucosal use in dogs and horses. Please call for more information.
J Vet Pharmacol Ther. 2005; 28(5):453-460.
PK-PD modeling of buprenorphine in cats: intravenous and oral transmucosal administration
Click here to access the abstract of this article.
Vet Ther. 2008 Summer;9(2):83-93.
Pharmacokinetics of buprenorphine following intravenous and oral transmucosal administration in dogs.
Click here to access the PubMed abstract of this article.
Sugar-Free Medications For Horses with EMS
The term “equine metabolic syndrome” (EMS) has been adopted to describe a collection of clinical signs that contribute to the development of laminitis in horses, and has previously been described as peripheral equine Cushing’s syndrome, pseudo-Cushing’s syndrome, hypothyroidism, and insulin resistance syndrome. Causes of EMS are similar to those found to cause metabolic syndrome and insulin resistance in humans. Management and prevention of EMS primarily revolves around weight control and prevention of obesity. While there is no “cure” for EMS, there exist many supportive therapies including vitamin and mineral supplements, low starch feeds, and anti-inflammatory and analgesic medications. While the horse feed industry has quickly realized the need for sugar-free feeds, any change in drug formulation requires FDA approval, so the veterinary drug industry has not been able to respond quickly to the need for sugar-free medications and supplements for horses.Our compounding pharmacy can contribute significantly to the care of EMS horses by working with veterinarians to convert all medications and supplements to sugar-free dosage forms. Sugar-free powders and pastes of phenylbutazone, flunixin, pergolide, and vitamins are particularly valuable to veterinarians treating horses with EMS.
Pergolide for Equine Cushing’s Disease
Pergolide has proven to be a safe and effective therapy in long term management of equine Cushing’s disease. The American Association of Equine Practitioners (AAEP) has been working with the FDA to develop options to provide veterinarians with continued access to pergolide to treat equine Cushing’s patients. FDA has indicated willingness to utilize regulatory discretion to allow compounding pharmacists to provide pergolide compounded from the pure substance until a manufactured source of pergolide can be made available.
J Vet Intern Med. 2002 Nov-Dec;16(6):742-6.
Treatment with pergolide or cyproheptadine of pituitary pars intermedia dysfunction (equine Cushing’s disease).
Click here to access the PubMed abstract of this article.
Electrolyte Paste to Restore Fluid and Acid Base Balance in Horses
“Prolonged exercise in horses, particularly when performed in hot and humid conditions, brings about large fluid and electrolyte loses which, if not restored, may impair thermoregulatory responses and result in hyperthermia.” In horses, administration of oral rehydration solutions (ORS) is problematic, because many horses refuse to drink fluids containing electrolytes. Therefore, administration of ORS typically requires placement of a nasogastric tube with its inherent risks. An alternative is to give a concentrated electrolyte mixture as a paste. Leon et al. of Department of Veterinary Clinical Sciences, University of Sydney, NSW, Australia studied six Thoroughbred geldings to determine “whether oral administration of a concentrated electrolyte paste would promote the restoration of fluid, electrolyte, and acid base balance as well as fluid and electrolyte deficits induced by furosemide administration” (a standard model which induces significant contraction of plasma volume and consistent electrolyte deficit against which the effects of treatment could be measured).”As a general conclusion, horses that received concentrated electrolytes [and had free access] to water consumed more water, regained more weight, lost considerably less electrolytes in urine, and maintained plasma electrolyte concentrations and acid base balance closer to baseline values than did those that had ad libitum access to water only.” Administration of electrolyte paste provided a more practical source than supplementation using feed or salt blocks.
Am J Vet Res 1998 Jul;59(7):898-903
Effects of concentrated electrolytes administered via a paste on fluid, electrolyte, and acid base balance in horses.
Click here to access the PubMed abstract of this article.
Progesterone for Estrus Induction in Mares
According to Robert R. Foss, DVM, progesterone in sesame oil, 150 mg per day, IM is equally as efficacious as altrenogest. The optimal formulation is the combination of progesterone and estradiol 17-beta; the addition of estradiol provides a greater feedback than progesterone alone, so cessation produces a more dramatic response. The estradiol is somewhat protective against exacerbation of endometritis. Dr. Foss commonly uses this combination at 150 mg progesterone and 10 mg estradiol 17-beta, IM, daily for 10 days. Estrus will usually begin in 6-8 days with ovulation around day 10-12. This combination has been effective in situations where altrenogest has failed.
114th IL VMA Proceedings, February, 1996
Prednisone (Oral) Ineffective in Horses
Jackson et al. compared the effects of prednisone with environmental management to environmental management alone for the treatment of heaves (recurrent airway obstruction), and reported that oral prednisone has no additional benefit.To be effective, oral prednisone must be absorbed and metabolized to its active form prednisolone. Robinson et al. designed a study with two objectives: 1) to compare oral prednisone with intravenous dexamethasone for the treatment of horses with heaves; and 2) to measure serum prednisolone levels in horses after oral administration of prednisone and prednisolone. Each of five horses received five drug formulations (prednisone and prednisolone in tablet and liquid form, as well as intravenous prednisolone sodium succinate as a positive control, all at a dose of 2.2 mg/kg) in a Latin square design study. Severity of airway obstruction was measured, and there were no significant differences between prednisone administration and no medication at any time. Prednisolone was detectable in serum immediately after intravenous administration, peaking at around 1000 ng/ml at 12 min. Oral administration of prednisolone tablets or liquid yielded peak serum prednisolone concentrations of 377-1032 ng/ml at 30-45 min. When horses received oral prednisone tablets or liquid, prednisolone never reached detectable levels in the serum. The authors concluded, “In order for the drug prednisone to be effective after oral administration it must be absorbed from the gastrointestinal tract and converted to the active drug prednisolone by the liver. Although trace serum levels of prednisone were detected, prednisolone never appeared in the serum. Our data do not allow us to determine if prednisone is poorly absorbed, rapidly excreted, or not converted to prednisolone by the liver. However, it is clear that prednisone is unlikely to have any anti-inflammatory effect when administered by mouth. Oral administration of prednisolone is likely to be beneficial because it is rapidly absorbed and achieves serum levels close to those that result from intravenous administration.”Robert N. Oglesby, DVM (The Horseman’s Advisor, www.horseadvice.com) reports his reaction to hearing the above presentation at the November, 2000 meeting of the American Association of Equine Practitioners: “I was shocked and looking around me hundreds of other vets were also: oral prednisone doses are in every equine medicine text with many descriptions of its indications. Why has no one noticed the lack of effect before now? The reason is simple: no one believed it was possible that [prednisone] was not effective [in horses]. Its usefulness in other species was too well established… we did not even question its use. Looking back on it, it was the management changes that were responsible for the clinical improvement…”
Equine Vet J 2000 Sep;32(5):432-8
AAEP Proceedings, Vol. 46, 2000, pp. 266-267
Equine Vet J. 2002 May;34(3):283-7
Prednisone per os is likely to have limited efficacy in horses.
Click here for access to the PubMed abstract.
We can compound prednisolone into the most appropriate dosage form, including oral pastes or “chewies” that horses will love!
PentoxifyllineIn horses, a dose of 8.5 mg/kg orally two times daily is recommended for reducing the cytokine effects in endotoxemia. For the treatment of navicular disease, 6 g/day orally for 6 weeks should be used.
Compendium 23(7), July 2001, 603-4
Anti-Diarrheals for Foals & Horses
Treatment of diarrhea should always be based on establishing a diagnosis and correcting the basic cause. Anti-diarrheal products are not a substitute for adequate fluid and electrolyte therapy when dehydration or shock threatens. When the veterinarian deems anti-diarrheal therapy is appropriate, the following options may be considered.According to James L. Becht, D.V.M., M.S., Diplomat ACVIM, preparations containing bismuth subsalicylate seem superior to those containing kaolin, pectin, or activated charcoal for treating the foal with diarrhea. Bismuth subsalicylate neutralizes bacterial toxins, has some antibacterial activity, and may exert an antisecretory effect. It can be administered at a dosage of 4 oz q 6h; darkened feces will result. If no effect is seen within 48 hours, continued administration is probably not indicated. (105th Ohio VMA).Wendy E. Vaala, V.M.D., Diplomate ACVIM reports (ACVIM 16th Veterinary Medical Forum) that delayed gastric emptying and gastroduodenal dysmotility can be improved in some foals with metoclopramide (0.25-0.6 mg/kg, PO q4-6h), erythromycin (1.0-2.0 mg/kg PO q6h), or cisapride (10 mg/kg PO q6h). If colic, ileus, and gastric reflux are present, Dr. Vaala recommends an abdominal sonogram to rule out the presence of an intussusception prior to initiating prokinetic therapy. Diarrhea may be treated symptomatically with bismuth subsalicylate (1-2 ml/kg, PO, q4-6h) and may also respond to psyllium administration. Intestinal probiotics containing Lactobacillus bacteria … may be given to foals receiving antibiotics to help reestablish intestinal flora.Adult horses may be treated with bismuth subsalicylate 1 oz per 8 kg of body weight PO TID-QID (Clark and Becht 1987).
Headshaking in Horses
May include additional signs such as nose rubbing, striking at the nose with the forelegs, or active avoidance of light, warmth, or wind on the face. Newton et al studied 20 mature horses with typical headshaking of 2 week to 7 year duration, and concluded that the etiopathology may be a trigeminal neuritis or neuralgia. In 12 of 20 horses, drug therapy was initiated. Cyproheptadine (CP) alone was ineffective but the addition of carbamazepine (CM) resulted in 80-100% improvement in 80% of cases within 3 to 4 days of beginning drug therapy. Seven cases were treated with a combination of CM (4 mg/kg, three to four times daily) and CP (0.2-0.5 mg/kg every 12 to 24 hours).Carbamazepine alone has been effective in 88% of cases. Some headshaking horses have responded well to CM doses of 1.6 – 2.4 grams every six hours without apparent side effects. Horses are treated for 10 to 20 days and if they respond, the treatment is discontinued. If clinical signs of headshaking recur, treatment is restarted. In practice, there is a realistic possibility of controlling but not curing headshaking with carbamazepine therapy at the present time. Other studies have reported that cyproheptadine alone was beneficial in more than two thirds of treated horses.
Equine Vet J 2000 May;32(3):208-16
Headshaking in horses: possible aetiopathogenesis suggested by the results of diagnostic tests and several treatment regimes used in 20 cases.
Click here for access to the PubMed abstract.
Equine Vet J Suppl 1998 Nov;(27):28-9
Characterisation of headshaking syndrome–31 cases.
Click here for PubMed abstract.
J Am Vet Med Assoc 2001 Aug 1;219(3):334-7
Owner survey of headshaking in horses.
Click here for access to the PubMed abstract.
ISU Vet Med Sept 2000
The Pennsylvania State University Veterinary News, Dec 2000, pp 9-10
Aust Vet J. 1991 Jul;68(7):221-4
Use of phenytoin to treat horses with Australian stringhalt
Click here for access to the PubMed abstract.
Avian
Doxycycline Administered in Drinking Water for Treatment of Spiral Bacterial Infection in Birds
Spiral bacteria have been found in various portions of the respiratory tracts of cockatiels and lovebirds. Common signs of infection with this bacterium include red clogged nares, sneezing, reddened and blunted choanal papillae and pharyngeal redness. Infected birds may also show signs of lethargy, anorexia and weight loss. Conjunctivitis, sinusitis and periorbital swelling may also be noted but are less common signs. A survey of 148 cockatiels seen by a veterinary practice in New York indicated that 37 (25%) were found to be infected with spiral bacteria with most of these having clinical signs of upper respiratory tract infection and red choana. The infection rate was higher in birds <2yrs old and in birds fed poor diets, suggesting that spiral bacteria are opportunistic organisms that cause clinical signs in young and compromised birds.Spiral bacterial infections in cockatiels have been successfully treated with oral administration of doxycycline hyclate at 25mg/kg orally every 12 hours for 3 weeks. However, this regimen requires twice-daily capture and forced administration of doxycycline liquid suspension, which is apparently not palatable to birds. The stress caused by this regimen to both birds and owners caused researchers at the North Carolina State University College of Veterinary Medicine to determine the feasibility of administering doxycycline via drinking water. A group of 11 cockatiels naturally infected with spiral bacteria were offered solutions of doxycycline at 400mg per liter as the sole source of drinking water and 7 other naturally infected cockatiels acted as the control group receiving untreated tap water as the sole source of drinking water for a treatment period of 30 days. For the first 14 days, spiral bacteria were isolated from all 18 birds in both the treatment and control group, but after day 21, spiral bacteria were no longer seen in the treatment group.For this study, doxycycline drinking water was prepared by emptying the contents of 4 x 100 mg doxycycline hyclate capsules into a liter of deionized water and stirring with a magnetized stirrer for 4 minutes and made fresh every 24-36 hours. As most bird owners do not have magnetic stirrers at home, and as the doxycycline hyclate capsules contain excipients other than doxycycline that do not go into solution and settle out at the bottom of the drinking bowl, our compounding pharmacy can provide bird owners with a more efficient method of doxycycline hyclate delivery by preparing 400mg capsules or packets of pure doxycycline hyclate, which the owner can stir into a 1 liter bottle of sterile water for irrigation (eliminating the possibility of contamination as well as preventing any binding of doxycycline by cations in tap water). It is interesting to note that doxycycline monohydrate is more palatable than doxycycline hyclate, but unfortunately, doxycycline monohydrate is not soluble in water and would not be a useful salt for this method of drug administration.
J Am Vet Med Assoc. 2008 Feb 1;232(3):389-93
Administration of doxycycline in drinking water for treatment of spiral bacterial infection in cockatiels.
Click here to access the PubMed abstract of this article.
Antifungal Therapy for Avian Species
In avian species, the most frequent causes of infection have shifted from gram-negative bacteria to gram-positive bacteria and Candida (often non-albican) species. There is a decreased susceptibility of many non-albicans species to available antifungal drugs, perhaps as a consequence of nondiscriminate azole use.The efficacy of terbinafine has been improved when administered in combination with azoles for treatment of azole resistant oral candidiasis and aspergillosis. Because terbinafine was administered successfully in an African gray parrot at 15 mg/kg every 12 hours for 30 days without adverse effects, it may have potential for use in systemic aspergillosis in these azole-sensitive species. Caution should be used in avian patients with liver or renal disease.
Veterinary Clin North Am Exot Anim Pract. 2003 May;6(2):337-50, vi
Antifungal drug therapy in avian species.
Click here to access the PubMed abstract of this article.
Treatment of a Systemic Fungal Infection in a Parrot with Itraconazole Flavored Suspension and Nebulized Clotrimazole
Submitted by Michael Briggs, Pharm.D.
A Solomon Island Eclectus parrot, female aged 1.5 years, presented in a weakened state. Examination and culture revealed a systemic Aspergillus infection. Due to its significant cost as well as concern for the pet, the owner was highly motivated to treat the parrot.
Treatment posed a challenge because the parrot only eats brightly-colored foods, and there was no commercially available clotrimazole solution for nebulization for veterinary use. The veterinarian contacted the local compounding pharmacy to discuss how compounded medications might help solve this therapeutic dilemma. It was decided that an oral suspension flavored with equal parts orange, banana, and strawberry could mask the bitter flavor of itraconazole, and that a customized dosage (20mg/ml) could be compounded for the parrot. The veterinarian also prescribed clotrimazole 1% for nebulization.
The owner administered 0.2ml (4mg) of itraconazole suspension to the bird each day by mouth using an oral syringe. Therapy continued for three months. Clotrimazole 1% solution was nebulized (1ml BID to TID) by placing a pediatric nebulizer mask over the cooperative bird’s head. After 30 days, the bird still had a productive cough. Therefore, nebulizer therapy with clotrimazole continued after total resolution of signs and symptoms of infection, for a total of four months (one month after the oral itraconazole was finished).
The parrot fully recovered. This case represented the pharmacy’s first attempt at avian therapy, and was 100% successful. The same therapy was used later for another bird that also fully recovered from a systemic Aspergillus infection.
Enrofloxacin in Birds
Enrofloxacin is highly active against most gram-negative bacteria. Doses of 15 mg/kg orally twice daily have maintained effective drug concentrations in most of the psittacine species that have been tested. Senegal parrots have required TID dosing for moderately resistant organisms. Keven Flammer, DVM, Dip ABVP, reports successful treatment of E coli, Klebsiella, and Proteus infections. He states that oral administration is well tolerated, but that IM administration should be avoided, and never used for repeated dosing, due to irritation at the site of injection. The IM formulation can be given orally but is unpalatable, even when mixed with flavoring. Dr. Flammer notes that an oral suspension can be compounded and appropriately flavored.
10th U Wisc Exotic Pet Conf Procd 04:01
The Capsule Report, Small Animal/Exotic Edition Jan 2002;20, 10: page 3
Haloperidol for Feather-Plucking and Self-Mutilation
Neuropeptides, particularly dopamine, are implicated in many self-mutilating disorders. The 1993 Proceedings of the Association of Avian Veterinarians (pg. 119-120) reports the dopamine antagonist haloperidol is currently being used on cockatiels, lovebirds, ring-neck parakeets, African Greys, and several species of cockatoos and Amazon parrots. The indications for use in these birds have included severe feather plucking, mutilation of skin and muscle over the back, chest and legs, wing web mutilation, and Amazon foot necrosis syndrome. Side effects from the use of haloperidol have included depression, depressed appetite, excitability and anorexia. (In most birds, side effects disappeared after discontinuing the drug for several days and then retrying at a lower dose.) One study reported normal behavior was maintained “by administering haloperidol at approximately 0.4 mg/kg body weight/day for approximately seven months.”
Journal of Small Animal Practice 1993; 34:564-566
Treatment of psychogenic feather picking in birds with a dopamine antagonist.
Haloperidol for Feather Plucking
by Stacie Fowler, D.V.M., Texas
Signalment: “Echo”, adult male Eclectus Parrot
Chief Complaint: Feather picking of 4-6 years duration
Diagnosis: Previous veterinarian had done numerous tests in 1993 to rule out medical causes of feather picking and the final diagnosis was psychological behavioral feather picking.
Feather Picking: This is a common syndrome in pet “parrot-type” birds that can have medical and/or psychological causes. It is important to rule out all medical causes of this condition before initiating psychotropic drug therapy. It is also important to institute appropriate dietary and environmental changes as well as behavioral therapy along with psychotropic drug use.
Past History and Medications: Echo first started picking at his feathers in 1991. By November of 1994 he had pulled out all his feathers except those which he could not reach on his head. In December of 1994, Echo’s previous veterinarian started him on naltrexone (dose unknown) for behavioral feather picking. He failed to respond to this drug and was placed in an Elizabethan collar on 4/20/95 to prevent further plucking. The author first saw this patient on 1/10/97. He had been wearing the collar almost constantly since 4/95 and all his feathers were in place (but ragged and unkempt looking) except under the collar. Anytime the collar was removed the patient would rip his feathers out. The owners wished to try Prozac? for Echo’s problem but since this author has had little success with Prozac?, we started trials on other drugs. Along with changes in diet and environment and behavioral exercises, we started Echo on Aventyl? elixir at 1/4 teaspoon per 4 ounces of drinking water to be replaced with fresh twice daily. We also initiated every other daily misting of the feathers with a dilute Aloe and Penetran? suspension. By 3/8/97, Echo was still plucking too many feathers when the collar was removed. To his Aventyl? therapy, we added naltrexone compounded to 5 mg/ml in a strawberry flavored base, 0.16 ml by mouth twice daily. By 3/20/97 he was still plucking badly when the collar was removed.
The Aventyl and naltrexone were discontinued and we did a brief trial on diazepam 2 mg per 4 ounces of drinking water. The diazepam is not meant to sedate and the owner was instructed to increase the dose to a maximum of 10 mg per 4 ounces of water if feather plucking continued but only if no sedation was noted. The diazepam produced no change in behavior and caused too much sedation for Echo. On 4/10/97 we began a trial on haloperidol 2 mg/ml at .015 ml by mouth once daily. The owners were instructed that they could increase the dose to maximum of .06cc of 2 mg/ml haloperidol twice daily. By 5/7/97, Echo’s owners reported that they were giving .075 cc of 2 mg/ml haloperidol twice daily and he seemed to be responding nicely. On 5/17/97 the haloperidol was refilled and compounded to 1 mg/ml to facilitate easier measuring. As of 9/2/98, Echo is receiving haloperidol 0.15 mg by mouth twice daily. This is a higher dose than I have seen published in the literature but the owners are pleased with Echo’s condition and do not wish to try a lower dose or even possibly wean him off the haloperidol. Echo is not experiencing any noticeable side effects from his haloperidol therapy. Currently, Echo never wears his Elizabethan collar and is totally feathered in except for his neck. I believe that 2 years of constant pressure from the collar has caused atrophy of the feather follicles around the neck.
Miscellaneous
Prednisone versus Prednisolone: Which drug for which species?
While prednisone and prednisolone have historically been considered therapeutically equivalent when used in veterinary medicine, recent studies have proven that they are not. It is now well-accepted in veterinary medicine that while prednisone and prednisolone may be therapeutically equivalent in dogs and humans, they are not in cats and horses. Researchers Graham-Mize and Rosser administered 10 mg total dose of either prednisone or prednisolone to cats in order to determine comparative pharmacokinetics of each drug. The AUC (ng/ml/hr) and Cmax (ng/ml) of oral prednisolone was 5 fold and 11 fold higher following administration of prednisolone compared to an equivalent oral dose of prednisone: 3230 and 1400, respectively, following oral prednisolone compared to 672.63 and 122, respectively following oral prednisone. Although the study was not designed to discriminate differences in oral absorption versus hepatic conversion, the authors nonetheless demonstrate the superiority of oral prednisolone to prednisone in cats. Until further studies are conducted, most veterinary clinicians agree that prednisolone (not prednisone) should be utilized in feline patients.In 2002, researchers had demonstrated a superiority of prednisolone over prednisone in treating horses with recurrent airway obstruction (heaves). In this crossover study, 5 horses were given the following treatments: prednisone tablets, prednisone liquid, prednisolone tablets, prednisolone liquid and i.v. prednisolone sodium succinate (positive control). Blood samples were taken before drug administration and at selected time points during a 24 hour period. Serum concentrations of prednisone and prednisolone were determined in order to evaluate gastrointestinal absorption and hepatic metabolism. Serum concentrations of the endogenous glucocorticoid hydrocortisone were also determined as an indicator of the biological activity of the drugs. Both prednisolone tablets and liquid were absorbed rapidly, with prednisolone detectable in serum within 15 min of administration and with peak concentrations occurring within 45 min. Small amounts of prednisone were detected in the serum samples after administration of both prednisone tablets and liquid. The active metabolite prednisolone was not detected in serum samples after administration of prednisone liquid and was detected in serum samples from only one horse after administration of prednisone tablets. Endogenous hydrocortisone production was suppressed when horses received prednisolone. The results of these studies indicate that prednisone has poor efficacy for the treatment of heaves because it is poorly absorbed and the active metabolite prednisolone is rarely produced. In contrast, prednisolone tablets have excellent bioavailability and should be useful as a therapeutic agent in horses.Consult our compounding pharmacist about customized dosage forms and strengths. Caution: Transdermal application of prednisolone (or other corticosteroids) to the ear is not recommended due to a high likelihood of epidermal atrophy of the ear pinnae with chronic use. The ear tips will flop with time and may not return to normal shape even after withdrawal of the prednisolone.
Veterinary Dermatology 15 (s1) 2004, pp 10.
Bioavailability and activity of prednisone and prednisolone in the feline patient.
Click here to access the PubMed abstract of this article.
Equine Vet. J. 2002 May;34(3):283-7
Prednisone per os is likely to have limited efficacy in horses.
Click here to access the PubMed abstract of this article.
Safety and Efficacy of Ocular vs Parenteral Apomorphine for Induced Emesis in Dogs
A study published in October 2008 retrospectively evaluated the efficacy of a compounded 2mg ocular insert of apomorphine versus a compounded 1mg/ml apomorphine injection. Either parenteral or ocular apomorphine dosage forms were sent to veterinary clinics with a case study report form requesting case-specific information. Information collected included breed, body weight, time from placement of the insert until emesis, and any information available regarding the nature of the toxin and clinical signs. Clinicians were asked to grade the severity of adverse effects on a subjective scale of 0 to 5, with 5 being most severe and 0 being absent. The adverse effects listed included prolonged vomiting, tachycardia, excitation, respiratory depression, bradycardia, sedation, and ocular irritation. Hypotension was not specifically included because of the difficulty of monitoring this while treating the dog. The clinician was also asked to grade the ease of product use for each case. Case reports for more than 5000 dogs were ultimately reviewed.For the ocular insert group, approximately 67% of dogs developed emesis between 3 and 10 minutes following placement of the insert. Approximately 83% of the dogs had emesis within the 15-minute time interval. Median time to emesis was 6 minutes, 7.2% of dogs experienced emesis after 15 minutes, and 9.3% did not have emesis at all. When the drug was administered IV, emesis occurred rapidly with a success rate of 90.6% and a median time to emesis of 1 minute. Difference in success rate between the IV and ocular insert groups was not significant (p=0.399).The prevalence of adverse effects with the IV route was less than the ocular route; however, the prevalence of tachycardia and sedation were higher with the IV group. Tachycardia was detected in 0.6% of dogs treated with the ocular insert and 15.6% of those treated IV. In the ocular insert group, sedation occurred with a frequency of 11.1%, whereas the IV group had a frequency of 43.8%. For the ocular insert group, ocular irritation in 82% of dogs was also reported, but of these, 80% had severity scores of 1, which meant detected but not clinically relevant. If reports with a score of 1 were disregarded, the frequency of irritation decreased to 16.2%. In 6.3% of dogs, the clinician experienced some difficulty with use of the insert, either in placing the insert or in maintaining the insert in the conjunctival sac; and some dogs actively resisted placement of the insert while other dogs were successful in dislodging the insert once it had been placed, leading to discontinuous administration. The ease of use scores seemed to become better with time, suggesting that with experience, the clinicians became more skilled in using the inserts.Researchers also observed that dogs weighing more than 25kg seemed less responsive to a 2mg ocular dose of apomorphine. Researchers concluded that an insert with a larger quantity of apomorphine should be utilized for larger dogs and that safeguards should be employed to prevent administration of larger dose inserts to smaller dogs.Apomorphine has not been commercially available to veterinarians for several years. For this reason, compounding pharmacists have been supplying apomorphine to veterinarians in various dosage forms to have immediately available for emergency use. Dosage forms include compressed tablets, powders for reconstitution into ocular or injectable solutions, and injectable solutions for parenteral administration. In light of the results of this study, it would appear that compounded ocular solutions might be superior to either injections or solid ocular tablets or inserts. Kits can be prepared containing apomorphine that can be reconstituted for use as an isotonic ophthalmic solution and subsequently can be administered as an injection if emesis is not successfully induced after ophthalmic administration. Veterinarians interested in obtaining these dosage forms or kits may contact our compounding pharmacy.
Am J Vet Res. 2008 Oct;69(10):1360-5.
Safety and efficacy of an ocular insert for apomorphine-induced emesis in dogs.
Click here to access the PubMed abstract of this article.
Pyridostigmine Oral Liquid for Treatment of Myasthenia Gravis
Myasthenia gravis (MG) is a common cause of generalized weakness in dogs and cats. With optimal care, the prognosis for remission and a normal life are good. “Unfortunately, drugs used to diagnose and treat myasthenia gravis are frequently unavailable” but during manufacturer shortages, compounding pharmacists can provide needed medications.The drug used most commonly to treat MG is pyridostigmine bromide at a dose of 1-3 mg/kg orally two to three times daily. “It is extremely important to note, however, that pyridostigmine bromide should not be compounded with methylcellulose-containing vehicles, as methylcellulose has been shown to completely inhibit the oral absorption of pyridostigmine from the gastrointestinal tract.2 For animals not responding to pyridostigmine, corticosteroids (e.g., prednisone for dogs, prednisolone for cats) can be administered at 0.5 mg/kg orally every other day. Immunosuppressive doses of corticosteroids are not recommended as they may worsen muscle weakness.”
International Journal of Pharmaceutical Compounding. Sep/Oct 2008; 12(5):398-401
Veterinary Compounding for Myasthenia Gravis
Click here to access the abstract of this article.2 Neurology 1981; 31(2):145-149.
Compounding for Feline Lymphoma
Feline lymphoma is one of the most common cancers in cats and presents with a variety of lesions and symptoms. Feline lymphoma, like human lymphoma, is classified into low, medium and high-grade categories depending on the anatomic location and degree of malignant cell growth in affected organs. There are many clinical reports published describing the diagnosis, treatment and prognosis of cats with lymphoma; however, there has been little correlation between treatment, histologic grade and clinical outcome. Until 1999 there had only been one published study that followed treatment and outcomes for a group of cats with intestinal lymphoma. Of 40 cats evaluated, 29 cats with low-grade lymphoma in this study had a significantly greater response (69%) to medical therapy (chlorambucil and prednisone) and underwent complete remission with a medical survival time of greater than 20.5 months.The 11 cats in the high-grade group (treated with a variety of multiple drug combinations) showed a much poorer response to therapy.A retrospective study reviewed 667 cases of feline lymphoma and identified cats suffering from low-grade lymphoma. This study concluded that 92% of cats treated with chlorambucil and prednisone responded to treatment for more than 2.5 years and showed a disease-specific median survival time of 967 days.Both of these studies indicate that the combination of oral chlorambucil and prednisone are excellent treatment modalities for cats suffering from low-grade lymphoma.The dosage range for prednisone or prednisolone for treatment of feline lymphoma is 5-10mg daily. In spite of the success demonstrated by treatment with prednisone in the previously mentioned studies, recent pharmacokinetic work indicates that prednisolone has a much better oral bioavailability (i.e., higher levels of drug in the body) as compared to prednisone in cats. Veterinarians may find that providing prednisolone instead of prednisone with chlorambucil may further increase remission rates and survival times in cats with lymphoma. Both prednisolone and chlorambucil are extremely bitter drugs and many cats object strongly to the taste. By collaborating with veterinarians and pet owners, our compounding pharmacist can play an active role in providing palatable, individualized oral chemotherapeutic regimens of prednisolone and chlorambucil for cats with lymphoma.
Eur J Comp Gastroenterol 1999;4:5–11.
Feline gastrointestinal lymphoma: 67 cases (1988–1996).
Click here for more information.
J Am Vet Med Assoc. 2008 Feb 1;232(3):405-10.
Outcome of cats with low-grade lymphocytic lymphoma: 41 cases (1995–2005)
Click here to read the PubMed abstract of this article.
VetDermatology. 2004; 15 (Suppl. 1):9.
Bioavailability and activity of prednisone and prednisolone in the feline patient.
Click here for more information.
Managing Tracheal Collapse in Toy and Miniature-breed Dogs
Collapsing trachea is a commonly recognized problem with toy and miniature-breed dogs (e.g., Toy Poodles, Yorkshire Terriers, Pomeranians, Maltese, Chihuahuas) that is associated with weakness of the tracheal cartilage resulting in collapse of the airway.Tracheal collapse can sometimes be helped with surgery, but medical management remains the treatment of choice. Treatment strategies involve cough suppression, and the drug therapy of choice has historically been the combination of hydrocodone and homatropine used orally three to four times daily.As long as shortages of commercially available hydrocodone/homatropine products continue, our pharmacy can play a valuable role in providing compounded hydrocodone/homatropine oral suspensions, capsules and chewable treats in canine-friendly flavors for dogs with tracheal collapse.
Vet Clin North Am Small Anim Pract. 2000 Nov;30(6):1253-66, vi.
Tracheal collapse. Diagnosis and medical and surgical treatment.
Click here to read the PubMed abstract of this article.
Cetirizine Pharmacokinetics in Cats
While chronic dosing studies and safety and efficacy studies in allergic cats still need to be conducted, that the pharmacokinetic profile of cetirizine suggests that it is a promising alternative to glucocorticoid therapy in allergic cats. Presently, commercially available forms of cetirizine are not easily adjusted to cats. Cetrizine tablets for adult humans are 10mg tablets and could be halved to achieve an appropriate dose for a 5kg cat.Cetrizine products labeled for human children are available in 5mg chewable grape-flavored tablets or a 1mg/ml grape-flavored syrup. Because of the flavoring and the volume of liquid that would have to be administered, cetirizine products labeled for human children would be very difficult to administer to cats.Commercially-available cetirizine dosage forms are not particularly cat-friendly, and because cetirizine shows much promise for therapy of allergies in cats, veterinarians may wish to contact our compounding pharmacy to assist in preparing dosage forms of cetrizine that can be easily administered to cats.
Am J Vet Res. 2008 May;69(5):670-4.
Pharmacokinetics of cetirizine in healthy cats.
Click here to read the PubMed abstract of this article.
Aspirin Therapy for Cats
A retrospective study in cats receiving high dose aspirin (> or = 40 mg/cat q72h) and cats receiving low-dose aspirin (5 mg/cat q72h) showed equally efficacious anti-platelet effect in either group but a significantly lower incidence of adverse effects in the low dose aspirin group.Capsules containing 5mg of aspirin can be compounded in lactose, flavored with various powdered flavors. Pet owners can administer the capsules intact, or if the act of pilling is too stressful for the cat, the contents of the capsule can be sprinkled in a small amount of moist food for the cat to consume at will.
Clinical effects and plasma concentrations of fentanyl after transmucosal administration in three species of great ape.“fentanyl can be administered transmucosally to captive orangutans and gorillas for sedation. With further study on formulation, it may also become useful in chimpanzee protocols. The transmucosal route may also be clinically useful for acute pain management.”
J Zoo Wildl Med. 2004 Jun;35(2):162-6
Clinical effects and plasma concentrations of fentanyl after transmucosal administration in three species of great ape.
Click here to access the PubMed abstract of this article.
Emergency Emetic Kits for Canine Drug Units
Canine members of police departments are frequently trained to detect drugs and other illicit substances. Although training techniques are now being modified to avoid ingestions, most dogs were historically trained to aggressively paw, mouth, or bite any object that was suspect. This behavior greatly increases the risk of oral ingestion of these very potent, very dangerous drugs. Veterinarians are now offering training and emergency emetics to police officers so that they may provide life-saving decontamination measures. Compounding pharmacists can work with local police and veterinarians to provide emesis kits to ensure that these valuable public servants are afforded the best chance for survival when faced with an accidental ingestion.
JAVMA, 2006 Apr 1;228(7):1028-32
Toxicologic hazards for police dogs involved in drug detection.
Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus
Maggs et al. of the College of Veterinary Medicine, University of Missouri examined the effects of orally administered L-lysine on clinical signs of feline herpesvirus type 1 (FHV-1) infection and ocular shedding of FHV-1 in latently infected cats. Fewer cats and eyes were affected by conjunctivitis, and onset of clinical signs of infection was delayed on average by 7 days in cats receiving L-lysine 400 mg once daily for 30 days, compared with cats in the control group. Significantly fewer viral shedding episodes were identified in the treatment group cats, compared with the control group cats. This dose caused a significant but short-term increase in plasma L-lysine concentration without altering plasma arginine concentration or inducing adverse clinical effects.
Am J Vet Res 2003 Jan;64(1):37-42
Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus.
Click here to access the PubMed abstract of this article.
DextromethorphanOf the seven major human cough suppressants, only dextromethorphanis indicated for treating cough in small animals. If after reviewing the indications and contraindications, cough suppression is desired, the available human products must be screened carefully as a very limited number contain dextromethorphan without other potentially harmful ingredients. Typically, the dose in dogs and cats is 1 to 2 mg/kg three to four times daily. Human products are not flavored to an animal®s taste, and may require administering a significant volume (typical strength is 15 mg/5 ml) to adequately dose an average size dog.
Stool SoftenersDocusate (DSS) can be used to assist in the passage of hard or dry feces that may occur secondary to dehydration or metoclopramide or other medications. While capsules hide the bitter taste, they can not be divided for appropriate dosing in smaller animals. The recommended dose in dogs and cats is 2 mg/kg once daily. For more severe cases, appropriately dosed DSS enemas may offer an alternative to phosphate-solution enemas.
Merck Veterinary Manual, 8th Edition, pp. 1691
Ursodiol for Gallstones
The purpose of this study, reported in Am J Health-Syst Pharm (Vol. 52) was to prepare an oral dosage form of the bile acid ursodiol (also known as ursodeoxycholic acid) from commercially available capsules and to determine the short-term stability of this formulation. The formula used for this extemporaneous compound was found to be stable for up to 35 days.
Ursodiol in a Dog with Chronic Hepatitis
A dog with severe cholestasis secondary to chronic hepatitis was treated with ursodeoxycholic acid (ursodiol) orally. After 2 weeks of daily treatment, the dog was more active and had an improved appetite. Monthly serum biochemical determinations and analysis of individual bile acid profiles documented improvement in hepatobiliary tests and a marked reduction in the concentrations of potentially hepatotoxic endogenous bile acids. These effects were maintained for approximately 6 months.Studies have found an extemporaneously compounded ursodiol suspension to be stable for up to 35 days refrigerated. This drug is well absorbed orally and enters the liver directly from the portal system, and is then secreted into bile. Ursodiol should be administered orally as the first-pass effect is vital for effectiveness.
J Vet Intern Med 1997 May-Jun;11(3):195-7
Use of ursodeoxycholic acids in a dog with chronic hepatitis: effects on serum hepatic tests and endogenous bile acid composition.
Click here to access the PubMed abstract of this article.
Aminocaproic Acid for Degenerative Myelopathy (DM) in Dogs
DM appears with relative frequency only in the German Shepherd breed (GSD); confirmation of the diagnosis is important in other breeds before assuming that they have DM of GSD. During the past two decades, R.M. Clemmons, DVM, Ph.D., and other researchers at the University of Florida have provided important new insights into the pathoetiology of DM. Recently, they have found that when combined with the history, neurologic signs, CSF protein concentration and EMG, an elevated CSF acetylcholinesterase level helps confirm the diagnosis. It is increasingly clear that DM is caused by an autoimmune disease attacking the nervous systems of patients, leading to progressive neural tissue damage. In many respects, DM is similar to Multiple Sclerosis in human beings.The Integrative Medical Approach to Treatment of Degenerative Myelopathy involves four basic approaches: 1) exercise, 2) dietary supplementation, 3) medication, 4) other supportive measures. Conventional medicine has little to offer patients with DM. On the other hand, use of exercise, certain vitamins and selected drugs have delayed or prevented progression of DM in many afflicted dogs.Clemmons et al have found 2 medications which appear to prevent progression or result in clinical remission of DM in up to 80% of patients – aminocaproic acid (EACA) and n-acetylcysteine (NAC). They propose that circulating immune-complexes lead to endothelial cell damage in the vessels of the CNS. Subsequently, fibrin is deposited in the perivascular spaces. When this degrades (point of action of aminocaproic acid), inflammatory cells are stimulated to migrate into the lesions. The inflammatory cells release prostaglandins and cytokines (point of action of vitamin E and C) which lead to the activation of tissue enzymes and the formation of oxygen free-radicals (point of action of acetylcysteine) which, in turn, leads to tissue damage.They recommend giving EACA as a flavored solution, 500 mg orally every 8 hours. A “source for EACA is to have a compounding pharmacy make the solution from chemical grade EACA.” The only side effects that have been attributed to EACA have been occasional gastrointestinal irritation. This has presented a problem only in a few patients, typically those with pre-existing GI problems. The only known drug interaction is with high dose estrogen compounds.N-Acetylcysteine is a potent anti-oxidant which has powerful neuroprotective effects. Clemmons et al give 75 mg/kg divided in 3 doses a day for 2 weeks; then, 3 doses every other day. The N-acetylcysteine must be diluted to a 5% solution; otherwise, it will cause stomach upset. “This new treatment is expensive unless purchased through compounding pharmacies.” NAC can produce vomiting (due to the sodium content of the pharmaceutical product, which requires high concentration of base to buffer) and may increase the bleeding time. Giving fresh ginger 30 minutes before NAC or administering NAC with food (or on a full stomach) often reduces this effect.The chances of successful treatment are improved if the therapy is begun early in the course of DM rather than later. A response to the drugs should be evident within the first 7-10 days.
Chlorpromazine for Anti-Emesis
Chlorpromazine (Thorazine®) is a phenothiazine and works at the emetic center, the chemoreceptor trigger zone, and peripheral receptors; it is this veterinarian’s “all purpose anti-emetic of choice” for cats.1 Chlorpromazine may cause extrapyramidal symptoms in cats when administered at high doses. The drug may discolor urine pink or red-brown, cause mild sedation, and may potentiate hypotension in dehydrated patients. Phenothiazines should not be given within one month of worming with an organophosphate agent. The recommended oral doses in dogs and cats is 3.3 mg/kg PO one to four times daily. Due to extensive first pass metabolism2, it may be necessary to reduce the dose in animals with liver disease. A liquid concentrate can be appropriately flavored for dogs or cats.
- Todd R. Tams, DVM, Dip ACVIM in CA VMA C/E Conf Procd, 2000
- Veterinary Drug Handbook 3rd edition, Donald C. Plumb, ed.; pp. 129-30
Managing Anorexia in Uremic Dogs and Cats
h4-receptor antagonists (cimetidine, ranitidine, and famotidine) can be useful to reduce gastric acid secretion. Increased gastrin concentrations in serum during chronic renal failure may stimulate excessive secretion of gastric acid and cause ulcer formation. Some uremic dogs and cats dramatically increase their interest in food and food intake after therapy with an h4 blocker. According to a presentation at the Atlantic Coast Veterinary Conference by Dennis J. Chew, DVM, Dip and C.A. Buffington, DVM, some uremic animals may need this medication for an extended period of time (months to rest of their lives). Much of the experience of these veterinarians has been either with cimetidine at an initial dose of 10 mg/kg, followed by 5 mg/kg PO BID or famotidine at 1 mg/kg daily.
The Capsule Report, Vol. 19, No. 10, Jan. 2001
Doxycycline for Prophylaxis and Treatment of Osteoarthritis in Dogs
Prophylactic administration of doxycycline (a tetracycline) has markedly reduced the severity of canine osteoarthritis (OA) in weight-bearing regions of the medial femoral condyle, and therapeutic administration of oral doxycycline has been shown to reduce the severity of articular cartilage breakdown in various animal models of OA. This disease modifying effect is associated with reductions in the levels of active and total collagenase and gelatinase in articular cartilage of the involved joint.A prospective, clinical study of eighty-one dogs with OA secondary to spontaneous cranial cruciate ligament (CCL) rupture concluded that doxycycline inhibits nitric oxide production in cartilage in dogs with CCL rupture, and that doxycycline may have a role in the treatment of canine OA. Dogs with OA secondary to CCL rupture were divided into 2 groups before surgery. The Doxy-CCL group (n = 35) received 3 to 4 mg/kg doxycycline orally every 24 hours for 7 to 10 days. The CCL group (n = 46) received no treatment. Synovial fluid, articular cartilage, synovial membrane, and CCL samples were collected during surgery or immediately after euthanasia from healthy dogs (control group). Total nitric oxide concentrations measured in cartilage were significantly lower in the Doxy-CCL group than in the CCL group, but were not different from those measured in the control group.In another study, ten healthy adult mongrel dogs underwent transection of the left anterior cruciate ligament, which resulted in a marked decrease in bone mass, with increased osteoclastic activity and increased bone formation. Doxycycline treatment did not significantly affect either bone formation or bone resorption. The authors concluded that doxycycline protects against joint breakdown in this OA model via inhibition of matrix metalloproteinases in articular cartilage, rather than through an effect on subchondral bone.
Vet Surg 2001 Mar-Apr;30(2):132-9
The effects of doxycycline on nitric oxide and stromelysin production in dogs with cranial cruciate ligament rupture.
Click here to access the PubMed abstract of this article.
J Rheumatol 1996 Jan;23(1):137-42
Effects of oral doxycycline administration on histomorphometry and dynamics of subchondral bone in a canine model of osteoarthritis.
Click here to access the PubMed abstract of this article.
J Rheumatol Suppl 1995 Feb;43:149-51
Modification by oral doxycycline administration of articular cartilage breakdown in osteoarthritis.
Click here to access the PubMed abstract of this article.
Vet Clin North Am Small Anim Pract 1997 Jul;27(4):863-81
Slow-acting, disease-modifying osteoarthritis agents.
Click here to access the PubMed abstract of this article.
Arthritis Rheum 1992 Oct;35(10):1150-9
Effect of stanozolol on body composition, nitrogen balance, and food consumption in castrated dogs with chronic renal failure.
Click here to access the PubMed abstract of this article.
Cisapride: a Prokinetic Drug
Cisapride (Propulsid® – Janssen Pharmaceutica), was removed from the U.S. and Canadian markets by its manufacturer because of serious cardiac effects in humans. However, cisapride is now available as a pure chemical for veterinary use only and can be compounded as per your prescription order.Cisapride is chemically related to metoclopramide, but unlike metoclopramide, it does not cross the blood-brain barrier or have antidopaminergic effects or cause extrapyramidal reactions. Cisapride “is more potent and has broader prokinetic activity than metoclopramide, increasing the motility of the colon, esophagus (in cats and guinea pigs), stomach, and small intestine… [Cisapride] has been used in managing gastric stasis, idiopathic constipation, gastroesophageal reflux, and postoperative ileus in dogs and cats. Practitioners found cisapride especially useful in managing chronic constipation in cats with megacolon; in many cases, it alleviated or delayed the need for subtotal colectomy. Cisapride was also used in managing cats with hairball problems.””Cisapride appeared to be well tolerated by dogs and cats. Adverse reactions to cisapride have not been reported to the United States Pharmacopeia’s Veterinary Practitioners’ Reporting Program… Disorders of GI motility are common and frustrating clinical problems in dogs and cats. Cisapride, with its extensive prokinetic action, was a welcome addition to veterinary medicine.””Life after cisapride: Prokinetic drugs for small animals.” Patricia M. Dowling, DVM, MS, DACVIM, DACVCP Veterinary Medicine, September 2000, pp. 678-685Doses:
Dogs –
As a promotility agent: initially 0.5mg/kg three times daily to reduce regurgitation associated with megaesophagus: 0.55mg/kg orally one to three times daily, no less than 30 minutes before feeding. As an antiemetic: 0.1-0.5mg/kg orally every 8 hours.
Cats –
For chronic constipation: initially, 2.5mg (for cats up to 10#) or 5mg (cats 11-15#), or up to 7.5mg (for cats over 16#) three times daily, 30 minutes before food, in combination with stool softener and bulk agent.
Cisapride is contraindicated in patients in whom increased GI motility could be harmful (e.g., perforation, obstruction, GI hemorrhage). Absorption of other orally-administered drugs may be affected. Cisapride may enhance anticoagulants’ effects; additional monitoring and anticoagulant dosage adjustments may be required. Cisapride may enhance the sedative effects of benzodiazepines. Clients should be advised to monitor the animal and report any adverse effects.
Veterinary Drug Handbook, 3rd edition, Donald C. Plumb, editor. pp. 139-140
Hairball Remedy
Cat and ferret owners continually search for specialized foods and treats that their pets will readily consume and will also be effective for hairball prevention or elimination. Call us for a customized, flavored hairball remedy for your patients!}
Managing Tracheal Collapse Patients
Collapsing trachea is a commonly recognized disease of toy and miniature-breed dogs. Treatment strategies involve cough suppression, and the drug therapy of choice has historically been hydrocodone.As long as shortages of commercially available hydrocodone/homatropine products continue, our pharmacy can play a valuable role in providing compounded hydrocodone/homatropine oral suspensions, capsules and chewable treats for tracheal collapse patients. While the ingredient homatropine may not play a significant role as a cough suppressant for dogs, inclusion of homatropine greatly discourages human abuse of hydrocodone by virtue of its anticholinergic side effects.We can compound as a canine-friendly flavor (e.g. liver).
Vet Clin North Am Small Anim Pract. 2000 Nov;30(6):1253-66, vi.
Tracheal collapse. Diagnosis and medical and surgical treatment.
Click here to access the PubMed abstract of this article.
Compounding for Feline Lymphoma
Feline lymphoma is one of the most common cancers in cats and presents with a variety of lesions and symptoms resulting from various cell types, degrees of dissemination and rate of progression.Recent studies have shown cats treated with chlorambucil and prednisone responded to treatment for more than 2.5 years. Recent pharmacokinetic work indicates that prednisolone has a much better oral bioavailability as compared to prednisone in cats. Both prednisolone and chlorambucil are extremely bitter drugs and many cats object strongly to the taste. By collaborating with veterinarians and pet owners, our compounding pharmacist can play an active role in providing palatable, individualized oral chemotherapeutic regimens of prednisolone and chlorambucil for cats with lymphoma.
Eur J Comp Gastroenterol 1999;4:5–11.
JAVMA, February 1, 2008; 232(3):405-410.
Outcome of cats with low-grade lymphocytic lymphoma: 41 cases (1995–2005)
Click here to access the PubMed abstract of this article.
Veterinary Dermatology 15 (s1) 2004, page 10
Mirtazapine for Appetite Stimulation in Dogs and Cats
Mirtazapine (Remeron™-Organon) is approved as an antidepressant for use in humans and has activity both as an alpha2 receptor antagonist and as a potent 5HT3 antagonist.A side effect noted in humans taking this drug is appetite stimulation. Pharmacy faculty at the Mississippi State College of Veterinary Medicine used mirtazapine in a dog after all other attempts at appetite stimulation had failed, and were very pleased to find that mirtazapine restored appetite almost immediately in this dog.In another case, a physician used mirtazapine to treat anorexia and nausea in his Boston Terrier with chronic renal failure. Due to the vast improvement in the animal’s quality of life for one month preceding its death, the dog’s primary care veterinary clinic conducted a series of uncontrolled field trials using mirtazapine over the next 4 years in 24 dogs and 17 cats with GI symptoms that were marginally responsive or refractory to standard remedies. “Mirtazapine therapy led to a robust response in 12 animals, improvement compared with standard treatment in 16 cases, and an equivocal response in 13 animals. The most vigorous responses were observed in patients in chronic renal failure or receiving concurrent chemotherapy for neoplastic disease.”Many veterinarians have started using mirtazapine to stimulate appetite in both dogs and cats.There have been no controlled studies and dosing is still empirical, but most dogs are dosed at 0.6mg/kg orally every 24 hours and cats are dosed at 3.75mg/cat orally every 48-72 hours. The terminal half-life of mirtazapine in humans is more than 40 hours, and mirtazapine is eliminated partially through conjugation with glucuronide. For this reason, dosing intervals of less than 48 hours are not recommended for cats, as accumulation is likely. Mirtazapine is not commercially available in an oral suspension; however, compounding pharmacists have formulated suspensions upon the request of veterinarians and have anecdotally reported success with this dosage form. For cats that are vomiting as well as anorectic and cannot swallow or retain oral medications, veterinarians have instructed compounding pharmacists to formulate transdermal gels of mirtazapine (3.75mg/0.1ml), which also have left veterinarians with a positive impression of clinical efficacy. Obviously, further studies are needed to determine stability, safety and efficacy of these compounded dosage forms, but until such evidence is available, veterinarians may wish to try these dosage forms in cases that are refractory to traditional methods of appetite stimulation.
Veterinary Forum, February 2006, pages 34-36