Canine atopic dermatitis is one of the most common causes of pruritus in dogs. Management needs to be tailored according to the patient's clinical presentation. In many cases, localized antipruritic therapy is the appropriate choice if there are focal areas of intense pruritus. Tacrolimus is a macrolide immunomodulator that has been found to be useful in atopic dermatitis in humans. In this blinded, placebo-controlled study, 20 dogs with atopic dermatitis were randomly assigned to 0.1% tacrolimus ointment or placebo (petroleum jelly). The ointment was applied twice daily for 6 weeks. Patients were scored for inflammation and pruritus with a 10-point scale at 0, 2, 4, and 6 weeks, and tacrolimus ointment was found to be effective for the treatment of localized lesions of atopic dermatitis. Lesions showed a 50% improvement in 15 of 20 dogs (75%).

COMMENTARY: Tacrolimus ointment (Protopic) is a nonsteroidal option for treatment of localized lesions of canine atopic dermatitis, especially for local areas of intense pruritus (e.g., paws). The drug is expensive-the cost of a 60-gram tube ranges from $100 to $120 in my practice area, and with application Q 12 H in a 25-kg dog, this is approximately the amount needed to treat one focal lesion. The ointment may also be irritating: In this study, 5 of 20 dogs seemed to experience irritation. Skin irritation and a burning sensation at the site of application has been reported in humans.

Treatment of localized lesions of canine atopic dermatitis with tacrolimus ointment: A blinded randomized controlled trial. Bensignor E, Olivry T. VET DERMATOL 16:52-60, 2005.