Psychotropic compounds and veterinary medicine

Abstract

A 6-year-old, vaccinated, male neutered domestic shorthair cat was presented due to polyphagia and hypersexuality manifested since he had been adopted one year prior. Clinical and neurological examination was unremarkable, including absence of scrotal testicles and penile spines, indicative of testosterone absence. Differential diagnoses included inadequate neutering and residual testicular tissue, cryptorchidism, adrenal hyperplasia/neoplasia (sex steroid–producing), urinary bladder neoplasia, infectious myelopathy/neuropathy (e.g., feline infectious peritonitis [FIP]), temporal lobe epilepsy, or primary behavioral disorder. Hematology, biochemistry, and thyroid profile were almost unremarkable. Serology for Feline Immunodeficiency Virus, Feline Leukemia Virus, and Feline Coronavirus was negative. Serum pre- and post-human chorionic gonadotropin hormone stimulation Serum pre- and post-human chorionic gonadotropin hormone (hCG) stimulation testosterone ruled out cryptorchidism. Abdominal ultrasound revealed mildly enlarged colonic lymph nodes, the cytology of which revealed mild reactive hyperplasia. Urinalysis and culture were positive to Enterococcus spp. Magnetic resonance imaging of the brain and spinal cord and cerebrospinal fluid analysis was unremarkable. polymerase chain reaction in the cerebrospinal fluid for Toxoplasma gondii, FPV, FCoV, and bornavirus was negative. Attempts to treat hypersexuality as a behavioral disorder, urinary tract infection (amoxicillin clavulanic acid), pain (meloxicam and diazepam), and anxiety (diazepam) were unsuccessful. Thus, phenobarbital was prescribed in a low dose (1 mg/kg PO q 12h) which eliminated the episodes of polyphagia and hypersexuality without sedating the cat. Phenobarbital withdrawal resulted in hypersexuality re-establishment. Two years later, the cat remained episode-free on phenobarbital. Hypersexuality in male cats is characterized mainly by biting the nape, mounting, pelvic thrusting, penile erection, coital intermission, ejaculation, and/or masturbation. Temporal limbic structures play a significant role in the regulation of sexual arousal independently of testosterone. Hypersexuality has been associated with temporal lobe epilepsy in cats experimentally, while along with other clinical signs such as polyphagia, it is an established condition in humans called Klüver-Bucy syndrome. This is the first report to describe phenobarbital as a successful treatment of hypersexuality and polyphagia in a male neutered cat, raising a suspicion of feline Klüver-Bucy syndrome and temporal lobe epilepsy origin of these signs.