Retrospective evaluation of cyclosporine in the treatment of presumed idiopathic chronic hepatitis in dogs.

backgroundThe etiology of idiopathic chronic hepatitis (ICH) in dogs is poorly understood, but evidence supports an immune-mediated pathogenesis in some dogs.

objectivesTo describe a case series of dogs with presumed ICH treated with cyclosporine (CsA) with or without concurrent medications and to document the incidence of biochemical remission and factors associated with failure to attain remission. ANIMALS: Forty-eight client-owned dogs diagnosed with presumed ICH, treatment of which included CsA.

methodsTwo-institution, retrospective case series of dogs between 2010 and 2017. All dogs were treated with CsA with or without concurrent medications for ≥2 weeks. Data were collected from medical records.

resultsBiochemical remission (<1.1 times the upper limit of normal for alanine aminotransferase activity) was attained in 79% of dogs (38/48). Median dose of CsA at remission was 7.9 mg/kg/d (range, 2.5-12.7 mg/kg/d) and median time to remission was 2.5 months (range, 0.75-18 months). Concurrent hepatoprotectant treatment was not associated with likelihood of remission. Clinical score, ascites, hypoalbuminemia, hyperbilirubinemia, prolonged coagulation times, dose, and duration of treatment were not associated with the probability of remission or time to remission. Common adverse effects of CsA were gastrointestinal signs in 38% (18/48) and gingival hyperplasia in 25% (12/48) of treated dogs. CONCLUSION AND CLINICAL IMPORTANCE: A treatment regimen including CsA and frequent hepatoprotectant use resulted in biochemical remission of ICH in most dogs. None of the evaluated factors, including hepatoprotectant use, were significantly associated with likelihood of remission. Future prospective studies are indicated to evaluate CsA monotherapy in ICH dogs.