Some info on mites and bacterial skin infection in goats and treatment
More information on Mites Page 30
Also found more information here: Page 211
Also goats can be infected with Psoroptes Cuniculi which is the ear mite of rabbits. This can affect goats ears and can spread. You can diagnose these with a microscope in accordance to the methods described in a previous post or may be able to see these within the external ear canal using a magnifying glass. There is no evidence which supports cross-contamination of these in goats. In other words, you can have one affected but not all.
Link to treatment recommended for ear mites in goats. You can also pick this up at some feed stores.
A less likely possibility is lice. Several species of lice infest goats and separate species may occur on different species of goats. Two species of blood-sucking lice are found on goats; the goat-sucking louse and the African goat louse. These species are similar in appearance and are bluish-gray.
There are three species of chewing or biting lice parasites on goats. Bovicola crassipes (Rudow), a large yellow louse, and the Angora goat biting louse are normally found on Angora goats. The goat biting louse, Bovicola caprae (Guret) is commonly found on meat goats.
The presence of lice on goats is accompanied by scratching and rubbing. The effect depends on the number of lice present. Blood-feeding lice cause the most severe symptoms. Excessive feeding causes scabby, bleeding areas that may lead to bacterial infection.
There are also Vitamin deficiencies that can result in hair loss.