Outbreak of sarcoptic mange in alpacas (Vicugna pacos) and control with repeated subcutaneous ivermectin injections.

An outbreak of sarcoptic mange was investigated in an alpaca herd. Clinical disease occurred 2 months after the introduction of four alpacas with dry seborrhoeic skin lesions, the cause of which was not investigated. Initially a group of females was affected, despite repeated topical treatment with ivermectin at a dose of 0.5mg/kg bodyweight. One female died and post-mortem examination indicated sarcoptic mange as the cause of death. Infection with Sarcoptes scabiei was also demonstrated on microscopic examination of skin scrapes taken from clinically affected cohorts. Later in the outbreak, a separate group of male alpacas was also affected. Treatment using subcutaneous ivermectin injections at a dose of 0.2mg/kg, administered at 14-day intervals, was evaluated. During this course of treatment, another female died. A successful response in the other alpacas was eventually reached following 12 treatments of the female group and 8 treatments of the male group.