Efficacy and safety of selamectin against Sarcoptes scabiei on dogs and Otodectes cynotis on dogs and cats presented as veterinary patients

A series of randomized, controlled and masked field studies was conducted i n veterinary patients to evaluate the efficacy of selamectin, a novel averm ectin, in the treatment of naturally occurring Sarcoptes scabiei infestatio ns on dogs and Otodectes cynotis infestations on dogs and cats. A total of 342 dogs and 237 cats participated in these studies, which were conducted a t 40 veterinary practices in the USA and Europe. Animals were randomly assi gned to treatment with selamectin or a positive-control product (existing a pproved products). Selamectin was administered as a unit dose providing a m inimum of 6 mg kg(-1) (range: 6-12 mg kg(-1)) in a topical preparation appl ied to the skin in a single spot on day 0 (O. cynotis in cats, n=144), or o n days 0 and 30 (O. cynotis and S. scabiei in dogs, n=83 and n=122, respect ively). The presence of parasites was assessed before treatment and at 30 d ays (for all studies) and 60 days (for O. cynotis and S scabiei dog studies ) after first treatment. The animals were also evaluated clinically at each assessment period. Based on skin scrapings, the efficacy of selamectin aga inst S. scabiei infestations on dogs was >95% by day 30, and 100% by day 60 . Against O. cynotis, selamectin eliminated mites in 94-100% of cats by day 30, and in 90% of dogs by day 60. The positive-control products achieved s imilar results. Thus, selamectin was safe and effective against ear mites i n dogs and cats and sarcoptic mange in dogs when used in field (veterinary patient) studies in dogs and cats of a wide variety of ages and breeds. (C) 2000 Elsevier Science B.V. All rights reserved.