Demodectic mange is a skin disease caused by the mite Demodex Canis ( this type of mite is confined to dogs, humans have a different one ) These mites live on the bodies of all dogs without causing any problems. However when the dogs immune system is malfunctioning it is unable to keep the mites under control . The problem can develop into generalised demodex with sores and red skin all over the body.
The mites are transferred to the puppy from the mother within the first week, in a normal puppy this is entirely natural and the puppy's immune system will control their numbers.
The puppies that are lacking immunity will begin to develop bare patches usually near the head, as the puppy matures these should disappear, it may however take months.
Diagnosis is easy and takes the form of a skin scrape or skin biopsy
For some dogs the immune system dosn't begin to function successfully and generalised Demodex is the result, the hair loss and reddened skin will spread over the entire body and the skin will become crusty and greasy, secondary infection will usually follow. The skin may or may not be itchy.
Generalised Demodex is a serious condition that needs immediate treatment, in some dogs the mites can never be controlled ,especially in older dogs or those with other immune conditions that may be under immunosuppressing treatment for their condition. The prognosis for these dogs is not good.
Older dogs that develop demodex should be checked for Hypothyroidism and Cushings disease as well as cancer
Treatment for localised Demodex is usually topical with ointments prescribed by your vet.
Generalised Demodex however is more serious and requires a more aggressive approach.
This usually means baths in an organophosphate every 2 weeks for possibly months with skin scrapes to determine if the mites are still present
This is not pleasant, the chemical is so toxic, it is very stressful for both owner and dog.
Demodectic Mange is not an inherited condition BUT the faulty immune system that cannot keep them under control can be. All puppies receive the mites from their mother but only the few with ineffective immune systems develop the disease.
Dogs with a familial history of demodex and parents and siblings of such dogs should not be bred.
This is a ist of oral or “spot-on” medications available in the UK that can be used to treat generalized Demodex. The list is from a veterinary dermatologist:-
Selamectin (marked as Stronghold in the UK and is approved for use in dogs; use for demodex treatment is off-label)
Ivermectin (Ivomec – approved for use in cattle; used off-label for dogs)
Doramectin (Dectomax – approved for use in cattle; used off-label for dogs)
Milbemycin (Moxidectin or Advocate; approved for use in dogs to treat Demodex)