There are in fact 3 different types of Demodex. It is thought that these are three different species but this is a little controversial.
1. Long bodied Demodex (Demodex injai)
This tends to show up in animals that are a few years old rather than juvenile. It is often found in dogs that have had corticosteroids for allergy control. It is usually found on the top of the dogs’ back and causes an excessively greasy dermatitis. It looks like the dog has rubbed under the car.
2. Demodex canis
This is the most common form. There is a localised form which may get better without treatment which has caused much confusion and tension between breeders and veterinarians. These are often young dogs with one or just a few small scaly areas with hair loss. These dogs aren’t actually immunocompromised and the mite seems to flare in “puberty” when oestrogen or testosterone surges in the body, much like teenagers with acne that grow out of it. This has given rise to many mythological and spurious treatments that actually did nothing in reality as the mange got better on its own.
This is quite separate from generalised Demodex. The head and forelegs are affected. The dog may have severe hair loss and pimples. Sometimes the lymph nodes are enlarged. These dogs have immune system dysfunction and will require intense and prolonged veterinary treatment for several months.
3. Short bodied Demodex. These mites live in the outer layers of the skin as opposed to the other types of demodex which live in the hair follicle. It is now thought that short bodied Demodex is actually contagious whereas the other Demodex species are not. Short bodied Demodex also causes scratching whereas it is rare for other Demodex species to cause itching
All information is of a general nature and copyright to Dr Rob.
For specific advice please consult Australind Vet Hospital.