Comparison of diazepam with progestin for effectiveness in suppression of urine spraying behavior in cats

The most common treatment for urine spraying and marking in cats has been administration of long-acting progestins. Treatment with diazepam has recently been gaining favor, particularly because of reported adverse effects of progestins. Results of a clinical trial involving 20 cats indicated that diazepam was effective in eliminating or markedly reducing spraying in 11 (55%) of them. However, most cats required continuous treatment, or at least intermittent treatment, when spraying recurred. The physiologic and behavioral dependency of cats on diazepam, which presumably develops over the course of administration, may contribute to the tendency for spraying to recur once diazepam treatment is discontinued. Using data from previously published findings on progestin administration, plus additional cases, it was documented that a significantly (P less than 0.05) higher percentage of males than females responded favorably. Although the number of cases was not sufficient for a statistical comparison of diazepam vs progestin treatment with regard to male vs female, possible gender difference in the effectiveness of diazepam was not indicated.