Effects of cetirizine in dogs with chronic atopic dermatitis: a randomized, double blind, placebo-controlled trial

It was the aim of this study to evaluate the effect of cetirizine in dogs with atopic dermatitis (AD), fulfilling Favrot's diagnostic clinical criteria. In a randomized, double blind, placebo-controlled study, the dogs received either 3 mg/kg cetirizine orally once daily (n=27), or a placebo (n=23) for 14 days, without concomitant medication. The effect was evaluated by means of a pruritus visual analog scale at the start (D0) and at D14. After 14 days, cetirizine had clearly no effect on the pruritus in dogs with chronic AD and there was no significant difference between the two groups. It is concluded that cetirizine (and likely H1 histamine receptor antagonists in general) should not be recommended for the control of pruritus in dogs with a long term allergy.