A neutered male, 51-kg, 3.5-year-old puma (Felis concolor) presented in February 1995 with episodic grand mal seizures 5 months after arrival to the Seneca Park Zoo in Rochester, New York. CBC, serum chemistry panel, blood lead assay, blood ammonia assay, serum IgG and IgM levels and conjunctival scraping for canine distemper virus, serum strychnine assay, Hemobartonella screen, serum titer evaluations for toxoplasma, FIV, FeLeuk, FIP, urinalysis, and CSF analyses including canine distemper titer as well as bacterial culture and cytology were noncontributory to an etiologic diagnosis.
Three treatment options were considered: phenobarbital (Lilly Corporate Center, Indianapolis, IN, USA) 2.5 mg/kg PO, BID; diazepam (Hoffmann-LaRoche, Inc., Nutley, NJ, USA) 0.16–0.33 mg/kg PO, TID; or potassium bromide 8–10 mg/kg PO, BID.1 Phenobarbital was chosen for proven efficacy and safety in cats.1,4 Phenobarbital (80 mg), given orally twice per day in a food item, controlled seizure frequency to no more than once per month. Trough serum phenobarbital level was 44 µg/dl at 80 mg PO, BID maintenance dosage. This phenobarbital serum level was slightly above the normal range reported for medicated, domestic cats (15–40 µg/dl).2 Liver enzymes (alkaline phosphatase, SGPT, SGOT and LDH) remained within normal range of values.3 After 2.7 years of phenobarbital therapy (80 mg PO, BID), the puma presented ataxic and semi-responsive 2 hours after the morning treatment. The serum phenobarbital level was elevated at 72 µg/dl.2 Serum chemistry values including liver enzymes were not elevated. Reduction of the phenobarbital dosage eliminated the ataxia and sedation but failed to prevent epileptic seizure frequency to no more than once per month. A change in treatment to diazepam (5 up to 35 mg PO, BID) alone or in combination with phenobarbital failed to control seizures. In February 1998, magnetic resonance images of the brain demonstrated absence of organic disease or structural defects, the most common cause of seizures in domestic cats.5 Potassium bromide was initiated at 5 mg/kg PO, BID and changed after 3 weeks to 15 mg/kg PO, SID. Potassium bromide appears, thus far, effective at controlling seizures in the puma at once-daily dosing and without the sedation observed with phenobarbital. Steady-state, potassium bromide serum levels will be collected after 4 months of treatment.
Epilepsy is a treatable disorder in exotic felids but requires monitoring for adverse effects of therapy, keeping treatment options flexible and fostering communications with zoo staff and visitors.
1. August JR. 1991. Consultations in Feline Internal Medicine. W.B. Saunders Co.
2. Braund KG. 1994. Clinical Syndromes in Veterinary Neurology. 2nd ed. Mosby-Year Book, Inc.
3. ISIS Medical Animal Records Keeping System, Version 5.15, Apple Alley, MN.
4. Quesnel AD, Parent JM, McDonell W, et al. 1997. Clinical management and outcome of cats with seizure disorders: 30 cases (1991–1993). J. Am. Vet. Med. Assoc. 210: 72–77.
5. Quesnel AD, Parent JM, McDonell W, et al. 1997. Diagnostic evaluation of cats with seizure disorders: 30 cases (1991–1993). J. Am. Vet. Med. Assoc. 210: 65–71.