Prognosis for treatment of adult-onset demodicosis in dogs: 34 cases (1979-1990).

Medical records of 41 dogs with adult-onset generalized demodicosis diagnosed between 1979 and 1990 were reviewed. Of the 41 dogs, 8 had hyperadrenocorticism, 5 were suspected or confirmed to have hypothyroidism, 10 had allergic disease and had been treated with corticosteroids, and 6 were receiving chemotherapy because of a neoplastic or immune-mediated condition. In the remaining 12, a concurrent underlying condition was not identified. Thirty-four of the dogs were treated with amitraz dips: 7 were cured, 22 were clinically improved but still had Demodex canis mites in skin scrapings and needed amitraz dips on a maintenance basis, and 5 did not improve with treatment and were euthanatized. Of the 13 dogs with a definitively treatable underlying disease (hyperadrenocorticism or hypothyroidism), 9 were treated for the underlying disease and for demodicosis: 4 were cured, 3 were improved but still had D canis mites in skin scrapings and required maintenance amitraz dips, and 2 did not improve and were euthanatized. Of the 16 dogs that were receiving chemotherapy or had allergic disease, 15 were treated for the demodicosis while still receiving treatment for their underlying disease: 1 was cured, 13 were improved but needed maintenance amitraz dips, and 1 did not improve and was euthanatized. Of the 12 dogs without an identifiable underlying problem, 10 were treated: 2 were cured, 6 improved, but needed maintenance amitraz dips, and 2 did not improve and were euthanatized.