Figure A.	Figure B.

Diagnosis:

This case exemplifies the tricky nature of scabies. Canine scabies is a nonseasonal, intensely pruritic, transmissible infestation with the Sarcoptes scabiei var. canis mite. The distribution pattern typically involves the ventral abdomen, chest, and legs, with classic lesions of crusting along the elbows and ears. These mites can be very difficult to find but should be suspected in dogs with nonseasonal, intense pruritus. Multiple skin scrapings are necessary, and only one mite, egg, or fecal pellet is needed for diagnosis. In this case, numerous superficial skin scrapings revealed one adult scabies mite with a cluster of ova and scybala (fecal pellets; FIGURE C). Approximately 75% to 90% of dogs with scabies that have ear lesions demonstrate a positive pinnal-pedal reflex.

Figure C. The white arrow points to sarcoptid ova. The black arrow points to the scybala or fecal pellets. Adult Sarcoptes mites are often very difficult to capture on a skin scraping sample.

Treatment:

Treatment is recommended for all suspected cases of scabies, even if no mites are detected. Clinical experience shows that topical selamectin applied every 2 weeks for a total of three doses cures most patients; other parasite preventives are also labeled for control of sarcoptic mange. In households with multiple dogs, all dogs should be treated regardless of whether they show clinical signs, as they can act as asymptomatic carriers.