Evaluation of the Effect of Two Dose Rates of Cyclosporine on the Severity of Perianal Fistulae Lesions and Associated Clinical Signs in Dogs

Abstract

To investigate the effect of cyclosporine (2 or 5 mg/kg every 24 hours) on perianal fistulae (PAF) lesions. Blinded randomized, prospective trial. Dogs (n = 20) with perianal fistulae. Dogs were randomly assigned to administration of either 2 mg/kg (n = 10) or 5 mg/kg (n=10) of cyclosporine orally every 24 hours for 8 weeks. Lesion surface area was measured, lesion severity was graded using a visual analog scale, and the presence and severity of clinical signs recorded every 2 weeks. Lesion variables were significantly reduced in both groups after 8 weeks and owners also reported a reduction in clinical sign severity. The 5 mg/kg dose rate significantly accelerated lesion resolution compared with 2 mg/kg. In the 2 mg/kg group, 20% of dogs had complete resolution of clinical signs and 10% had resolution of lesions. In the 5 mg/kg group, 40% of dogs had complete resolution of clinical signs and 60% had resolution of lesions. A dose rate of 5 mg/kg every 24 hours was more effective at reducing the surface area and severity of PAF lesions than 2 mg/kg every 24 hours but less effective at resolving PAF lesions than previous studies using dose rates > or =5 mg/kg every 12 hours. Cyclosporine at 5 mg/kg every 24 hours may be useful for the palliation of PAF lesions.