Psoroptic ear mites in dairy goats.

Of 24 adult dairy goats examined at necropsy, 21 were found to be infected with ear mites (Psoroptes cuniculi), but none had gross signs of ear scab. Clinical examination of approximately 200 live adult goats on 23 farms revealed ear scabs in only one animal; however, the frequency of head shaking and ear scratching was high. On one farm with 170 lactating does, most of 25 kids examined within 6 weeks of birth were found to be infested. Serial examination of growing kids on another farm revealed mites in the ears of kids by 10 days of age. The onset of clinical signs of ear mite infestation was evident in all kids on the property during the 3rd week of life. In one instance when infested adult goats and kids were penned with adult sheep and lambs, there was no evidence of cross infestation.