This study investigated effects of a fluoxetine (selective serotonin reuptake inhibitors; SSRI, 1 mg/kg) on pruritus in canine atopic dermatitis (CAD). After 4-weeks of base-line observation, 8 dogs with CAD entered a 2-months randomized, double-blind, placebo-controlled, crossover trial comparing fluoxetine with placebo. Clinical efficacy was evaluated using a Canine Atopic Dermatitis Extent and Severity Index (CADESI-03) and Pruritus Visual Analog Scale (PVAS). Six dogs completed the study [two out of eight dogs (both of them were Shiba Inu) dropped out from the study due to a depression]. CADESI-03 and PVAS between fluoxetine and placebo showed no significant difference statistically (P > 0.05 and P > 0.05 respectively). Fluoxetine showed no efficacy on pruritus in CAD. Further researches are needed for the treatment on pruritus of CAD.