During the last decade, oral
cyclosporin (CsA) has proven to be effective, in randomized controlled trials, for the treatment of
atopic dermatitis (AD) in human patients. The purpose of this blinded randomized controlled trial was to test the hypothesis that CsA was successful in reducing the gravity of clinical signs of AD in dogs. Thirty dogs with nonseasonal AD were randomly allocated to receive an oral
solution of either
NEORAL CsA (5 mg kg-1) or
prednisolone (0.5 mg kg-1) once daily for 6 weeks. Before, and 3 and 6 weeks after
therapy, skin lesions were graded by clinicians using the Canine AD Extent and Severity Index (CADESI).
Pruritus was assessed by the owners using a visual analog scale (
PVAS). In both groups, CADESI and
PVAS values were significantly lower at 6 weeks post treatment than before the initiation of
therapy (Friedman test, P < 0.0004). The percentage reductions in CADESI and
PVAS values from baseline were not statistically different between groups (Mann-Whitney test, P > 0.3). In this experiment, the tolerability and safety of oral CsA and
prednisolone appeared similar. One-fifth of dogs given oral CsA occasionally developed diarrhoea or soft stools. One dog that was given CsA developed a generalized papillomatous skin eruption during the second half of the trial. Our study provides randomized controlled trial evidence that CsA reduces the severity of clinical signs in dogs with nonseasonal AD. Moreover, the
anti-allergic efficacy of CsA appears comparable with that of
prednisolone. We propose that oral CsA should be considered as a valuable alternative to
glucocorticoid therapy in dogs with AD.