Objective—To determine efficacy and safety of
cyclosporine in the treatment of atopic dermatitis
among dogs in North America.
Design—Randomized controlled (phase 1) and openlabel
(phase 2) trials.
Animals—268 dogs with atopic dermatitis.
Procedure—In phase 1, dogs were randomly assigned
to be treated with cyclosporine (5 mg/kg [2.3 mg/lb],
PO, q 24 h) or a placebo. In phase 2, all dogs were
treated with cyclosporine for 16 weeks. Frequency of
cyclosporine administration was decreased if dogs
Results—At the end of phase 1, canine atopic dermatitis
extent and severity index (CADESI) scores for
dogs treated with cyclosporine were significantly
lower than scores for control dogs. Percentage of
dogs with severe pruritus decreased from 67% to
16% for the cyclosporine group but from 66% to only
61% for the control group. During phase 2,
cyclosporine dosage was decreased to every-otherday
administration in 39% of the dogs after 4 weeks.
After 12 weeks, 22% of the dogs were treated twice
weekly and 36% were treated every other day. After
16 weeks, CADESI score had decreased > 50% in
68% of the dogs and 47% of dogs had no or mild pruritus.
The most frequent adverse reactions were gastrointestinal
Conclusions and Clinical Relevance—Results suggest
that cyclosporine is efficacious for the treatment
of atopic dermatitis in dogs and that frequency of
cyclosporine administration can be reduced following
an initial induction period. The drug was well tolerated.
(J Am Vet Med Assoc 2005:226:1855–1863)