The efficacy of cetirizine hydrochloride on the pruritus of cats with atopic dermatitis: a randomized, double-blind, placebo-controlled, crossover study.

Background: Various antihistamines have been used in the management of feline atopic dermatitis, with variable reported benefit. To date, there have been no randomized, double-blind, placebo-controlled, crossover clinical trials on the use of this drug class in cats.

Hypothesis/objectives: To evaluate the clinical efficacy of cetirizine hydrochloride for the control of pruritus and dermatitis in cats diagnosed with atopic dermatitis.

Methods: In this randomized, double-blind, placebo-controlled crossover clinical trial, 21 client-owned cats diagnosed with mild to moderate nonseasonal atopic dermatitis were randomly assigned to two groups. Cats in each group received either 1 mg/kg cetirizine hydrochloride or placebo once daily per os for 28 days followed by a 14 day wash-out period. Treatments were then crossed over, and cats received placebo or cetirizine hydrochloride for another 28 days. Owners marked a pruritus severity scale before inclusion in the study and weekly throughout the entire study period. Lesions were scored by the clinician using a Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03 modified for the cat before enrolment and at day 28 of each treatment.

Results: Nineteen cats completed the study. There were no statistically significant differences between treatment with cetirizine hydrochloride and placebo for modified CADESI-03 or pruritus scores.

Conclusion And Clinical Importance: This study suggests that cetirizine hydrochloride cannot be recommended for the management of feline atopic dermatitis.