What is demodex?
Demodex are species of mites that normally live on the skin of dogs and cats in the hair follicles and sebaceous glands.
The 3 most common species of Demodex are:
- Demodex canis
- Demodex gatoi (affects cats more frequently)
- Demodex injai (long-bodied)
What causes mange?
Localised demodecosis is most common in young dogs around the face and paws. Due to an immature immune system, the mites over-multiply and cause a focal area of hair loss.
Generalised demodecosis is caused by immune compromise causing mites to proliferate in multiple sites over the body. This causes multiple sites of hair loss.
D. injai proliferation is common in terrier breed dogs and leads to greasiness of the coat as the mites multiply in the sebaceous glands of the skin (glands that produce the oils).
Demodicosis is NOT ITCHY which differentiates it from sarcoptic mange (Scabies) which is very itchy.
Diagnosis
Diagnosis is via skin scrape and microscopic examination. (D. injai may require skin biopsy for diagnosis)
Treatment
Localised demodecosis is usually self-limiting and will resolve on its own without treatment. Topical acaricidals (parasite treatments) may be prescribed.
Generalised demodecosis requires treatment with doromectin, ivermectin, NexGard or Bravecto usually for 8-10 weeks until 2 negative skin scrapes are achieved.