Sarcoptes scabiei var. canis refractory to ivermectin treatment in two dogs

• Published in: Veterinary dermatology Vol. 21; no. 6; pp. 608 - 612
• Main Authors: Terada, Yuri, Murayama, Nobuo, Ikemura, Hiroshi, Morita, Tatsushi, Nagata, Masahiko
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.12.2010
• Subjects: Animals; Antiparasitic Agents - therapeutic use; case studies; dog diseases; Dog Diseases - drug therapy; Dog Diseases - parasitology; Dogs; drug evaluation; Drug Resistance; drug therapy; fipronil; ivermectin; Ivermectin - therapeutic use; Male; Pyrazoles - therapeutic use; Sarcoptes scabiei; Sarcoptes scabiei - drug effects; Sarcoptes scabiei var. canis; scabies; Scabies - drug therapy; Scabies - parasitology; Scabies - veterinary; topical application
• ISSN: 0959-4493; 1365-3164; 1365-3164
• DOI: 10.1111/j.1365-3164.2010.00895.x

A 10‐year‐old castrated male Shih Tzu presented with severe generalized pruritus. Skin scrapings revealed the presence of Sarcoptes scabiei var. canis. A Yorkshire terrier in the same household simultaneously developed pruritus due to scabies. Both dogs were treated with 300 μg/kg ivermectin, at first orally and then subcutaneously at 14 day intervals. However, live mites were still found on day 35, and the skin condition deteriorated in both dogs. These findings suggested that the S. scabiei in these dogs was clinically refractory to ivermectin. The pruritus in both dogs rapidly and completely disappeared following topical fipronil administration. This appears to be the first report of canine scabies refractory to ivermectin treatment.