Several methods to control urine spraying in cats have been evaluated. Studies have reported that diazepam and buspirone are effective for reducing spraying, but these studies were not placebo-controlled. Two separate studies showed that facial pheromones and fluoxetine were more effective than placebo in controlling the behavior. This study evaluated clomipramine and determined appropriate dosages. Cats in the study had a minimum 1-month history of spraying against vertical surfaces at least twice per week. Cats with a medical condition that could interfere with urine spraying or cats that displayed inappropriate elimination behaviors (urination on horizontal surfaces or defecation outside the litter box) were excluded. Owners agreed to keep litter boxes clean. They were instructed not to punish the cats when spraying occurred and to reduce the cats' stress by increasing the frequency of feeding and owner-controlled play sessions. There were 67 cats in the study. Most (54) were neutered males. The study went for either 8 or 12 weeks. Sedation was the most frequent adverse event, reported in 32 of the 67 cats including 5 in the control group. One cat in the high-dosage group was removed from the study because of acute renal insufficiency. The cats were not evaluated after the treatment was stopped. Study supported by Novartis Animal Health, Inc

COMMENTARY: This is the first randomized, controlled clinical trial evaluating the efficacy and optimal dosage of clomipramine for treatment of urine spraying in cats. Moderate dosages (0.25-5.0 mg/kg, PO Q 24 H) of the drug seem to be effective in significantly decreasing the number of urine spraying events per day and were well tolerated, associated with minimal side effects.

Determination of the dosage of clomipramine for the treatment of urine spraying in cats. King JN, Steffan J, Heath SW, et al. JAVMA 225:881-887, 2004.