304 DISEASES/DISORDERS
Adult onset (dogs): often severe and refractory to treatment.
Adult onset: sudden occurrence is often associated with internal disease, malignant
neoplasia, and/or immunosuppressive disease; approximately 25% of cases are idio-
pathic over a follow-up period of 1–2 years.Avoid breeding dogs with the generalized form of demodicosis.
(a)(c)(b)Fig. 19.1.Demodex canismites from a skin scrapings. (a) Adult and eggs. (b) Nymphs. (c) Larva. Adults have
a well-defined body segments with eight legs; eggs are fusiform; Nymphs have eight legs but poorly defined
body segments; larva are slightly larger than eggs and have six legs.