This crossover study was performed in order to compare the effects of cetirizine, loratadine, and terfenadine in canine skin. Five healthy dogs were used. Cetirizine 0.5 mg/kg, loratadine 5 mg/kg and terfenadine 5 mg/kg were administered orally 4 hours before the experiment. Erythema indices and wheal size were assessed by Hexameter ($MX^{circledR}$ 18, CK, Germany) and skin reaction guide, respectively. Cetirizine-induced erythema inhibition was generally higher than other drugs and was significantly different from placebo. Cetirizine was superior to placebo at 3, 4, 5, 6, 7, and 8 minutes (p< 0.01). Cetirizine also was superior to placebo at 9 minutes (p< 0.05). Loratadine and terfenadine erythema inhibition were better than after placebo treatment from 4 to 9 minutes, but erythema index of terfenadine at 7 minutes was not observed probability of 95% and 99%. At 10 minutes, intradermal injection of the histamine caused a mean wheal dimension for placebo, cetirizine, loratadine and terfenadine, which were 13.25$pm$0.75 mm,7.5$pm$ 1.02 mm (53% reduction, p<0.007),6.2$pm$0.58 mm(43% reduction, p <0.01), and 8.4 $pm$0.67 mm(37% reduction, p< 0.05), respectively, comparing with placebo. Loratadine and cetirizine were good antihistamines for clinical therapy for atopic dermatitis in dog.