Objective—To determine the efficacy of triamcinolone acetonide topical solution (TTS) in dogs for use in reduction of clinical signs of pruritic inflammatory skin diseases of a known or suspected allergic basis and to evaluate adverse effects associated with TTS administration. Animals—103 pruritic adult dogs with known or suspected allergic skin disease. Procedure—Dogs were treated for 4 weeks with TTS or with vehicle solution (control dogs) in a multiplecenter study. Clinical signs were scored by owners and by examining veterinarians before and after treatment. Blood samples obtained before and after treatment were subjected to routine hematologic and serum biochemical analyses. Results—Treatment success, as defined by an improvement of at least 2 of 6 grades in overall clinical score, was evident in 35 of 52 (67%) TTStreated dogs (mean improvement, 1.98) and 12 of 51 (24%) control dogs (mean improvement, 0.29). For several criteria, TTS was significantly more effective than vehicle in reducing clinical signs. Minor alterations in hematologic determinations in TTS-treated dogs were limited to slightly lower total leukocyte, lymphocyte, and eosinophil counts after treatment. Minor adverse effects were reported by owners in 6 of 52 (12%) TTS-treated and 9 of 51 (18%) control dogs. Conclusions and Clinical Relevance—Triamcinolone used as a spray solution at a concentration approximately one-sixth the concentration of triamcinolone topical preparations currently available for veterinary use is effective for short-term alleviation of allergic pruritus in dogs. Adverse effects are few and mild and, thus, do not preclude prolonged treatment with the solution. (Am J Vet Res 2002;63:408–413)