This species of mite is a NORMAL inhabitant of hair follicles and occasionally the sebaceous glands of ALL domestic species.
They are host specific.
The mites feed on cells of the skin, having a life cycle of 20-35 days.
Survival away from the host is only about 1 hour.
In most instances this mite does not cause disease.
The actual mechanism by which Demodex mites proliferate to cause disease is not completely understood although some immunological deficiency plays a part.
Transmission of mites is considered to occur from the bitch to puppies in the first 2-3 days of life.
Demodectic mange presents in two forms –
LOCALISED – usually young dogs aged between 3-12 months appears as a diffuse area of hair loss, some redness, and scaly skin and is generally not itchy. These lesions are usually around the head or on the limbs. These cases have a good prognosis and response is mostly good if aided by treatment. Remission often does not fully occur until 1 to 1½ yeara of age.
GENERALISED- usually in dogs under 1½ years old, having an all over patchy (moth eaten) hair loss, some redness, scaling of skin initially, developing to more extensive skin changes with time. These include thickening and wrinkling of skin, seborrhoea secondary infections, itchiness (often intense), and enlargement of peripheral lymph nodes. Up to 50% of dogs less than 1-½ years undergo spontaneous remission; however once over this age recovery is rare.
Diagnosis is by skin scraping and/or skin biopsies.
Localised- oral dosing with Ivomec or similar parasiticide.
Generalised – as above
antibiotics for secondary infection.
- antiseborrhoeic shampoos
feeding a good balanced diet
© Forrest Hill Vets (2000) Ltd