Use of doramectin for treatment of notoedric mange in five cats

Five of 16 cats belonging to the same owner were brought to the veterinary hospital because of a 30-day history of signs of intense pruritus and alopecic and erythematous areas with bloody crusts. Notoedric mange was diagnosed and confirmed by microscopic examination of skin scrapings of all 5 cats. The remaining cats did not have clinical signs of mange, and Notoedres cati were not observed after microscopic examination of skin scrapings. A decision was made to treat all 16 cats with doramectin subcutaneously. In each cat, 0.1 ml of a 1% solution of doramectin was administered s.c. Body weights ranged from 2.9 to 7.1 kg (6.4 to 14.2 lb) in the 16 cats and the final doses varied from 143 to 345 micrograms/kg (65 to 157 micrograms/lb) of body weight, with a mean (+/- SD) of 270.4 +/- 64 micrograms/kg (122.9 +/- 29.1 micrograms/lb). The mean dose for the 5 affected cats was 292.2 +/- 44.8 micrograms/kg (132.8 +/- 20.4 micrograms/lb), with a range of 208 to 333 micrograms/kg (94.6 to 151.4 micrograms/lb). Lesions began to recede 1 week after treatment. Fifteen days after treatment, all 5 affected cats were clinically normal. Findings in our cats suggest that a single mean dose of doramectin of approximately 290 micrograms/kg is sufficient to control notoedric mange in cats.