CONDITION
Demodectic Mange
Why this matters now
Demodectic mange most commonly appears in puppies and young dogs under eighteen months of age, when the immune system is still maturing. Adult-onset demodicosis is less common and often suggests an underlying condition affecting immune function. Certain breeds appear more predisposed, though the condition can affect any dog.
The condition may begin as small patches of hair loss, often around the face or feet, and either resolve spontaneously (particularly localised forms in young dogs) or progress to involve larger areas. Secondary bacterial infection can complicate the picture, adding redness, pustules, and discomfort. Without treatment, generalised demodicosis can become severe and challenging to manage.
Signals & patterns
Early signals
Patchy hair loss around the face
Early demodectic mange often appears as small, well-defined patches of hair loss around the eyes, mouth, or muzzle. The skin in these areas may look slightly scaly but is often not obviously inflamed initially.
Hair thinning on the feet
The feet, particularly between the toes, are another common site for early demodectic lesions. Hair may appear thin or patchy in these areas.
Mild scaling without itching
Unlike many skin conditions, uncomplicated demodicosis is often not particularly itchy. The skin may appear slightly flaky or have a moth-eaten appearance.
Small hairless patches appearing suddenly
Owners may notice one or several coin-sized bald spots developing over days to weeks, often in young dogs.
Later signals
Widespread hair loss and skin changes
Generalised demodicosis involves larger areas of the body, sometimes most of the dog. The skin may become thickened, pigmented, and increasingly abnormal in appearance.
Pustules and crusting
Secondary bacterial infection often develops as the condition progresses, leading to pustules, crusts, and sometimes draining lesions. The dog may now become itchy and uncomfortable.
Swollen feet (pododermatitis)
Demodectic pododermatitis involves deep infection of the feet, causing swelling, pain, and draining tracts. This form can be particularly challenging to treat.
Click to read about the biological mechanisms
How this is usually investigated
Diagnosing demodectic mange typically involves identifying the mites through skin examination. Additional investigation may be needed to understand why the condition has developed, particularly in adult dogs.
Deep skin scraping
Hair pluck (trichography)
Skin biopsy
Investigation for underlying conditions
Bacterial culture
Options & trade-offs
Treatment for demodectic mange aims to reduce mite numbers, treat secondary infection, and support the immune system. The approach depends on whether the condition is localised or generalised, and the dog's age and overall health.
Isoxazoline treatments
Oral medications from the isoxazoline class (licensed for flea and tick prevention) have become widely used for treating demodicosis, often showing good efficacy.
Trade-offs: Generally well tolerated, though individual responses vary. Usually requires several months of treatment with repeat skin scrapings to confirm cure. Not all products are licensed specifically for demodicosis.
Monitoring localised cases
In young dogs with only one or a few small patches, the condition may resolve spontaneously as the immune system matures.
Trade-offs: Close monitoring is essential to ensure the condition does not progress to generalised disease. Some cases that initially appear localised may require treatment.
Antibiotics for secondary infection
When bacterial infection complicates demodicosis, antibiotics may be needed alongside mite treatment.
Trade-offs: Treatment duration depends on infection severity. Deep pyoderma may require extended courses. Treating infection alone without addressing mite overgrowth is insufficient.
Topical therapy
Medicated shampoos and washes may help manage secondary infection and support skin health.
Trade-offs: Generally used as an adjunct to systemic treatment rather than as sole therapy for generalised disease. Can be time-consuming for owners.
Addressing underlying causes
In adult-onset cases, identifying and managing any underlying condition affecting immune function.
Trade-offs: Essential for long-term success but not always straightforward to identify. Some underlying conditions require ongoing management.
Common misconceptions
"Demodectic mange is contagious to other dogs or people"
Unlike sarcoptic mange, demodicosis is not considered contagious under normal circumstances. Demodex mites are species-specific and are transferred from mother to puppies during nursing. Adult dogs do not typically catch demodicosis from affected dogs.
"Any hair loss with mites is demodectic mange"
Finding small numbers of Demodex mites on skin scraping is normal—they are part of healthy skin flora. Demodicosis is diagnosed when mite numbers are elevated and skin disease is present. Other conditions can cause similar-looking hair loss.
"Once treated, demodectic mange never returns"
While most dogs treated for juvenile-onset demodicosis do not have recurrence, adult-onset cases may relapse if underlying immune suppression persists. Follow-up monitoring helps ensure successful treatment.
Understanding whether your dog has localised or generalised demodicosis helps frame expectations for treatment duration and approach. Keeping track of affected areas and any changes can help monitor progress. Young dogs with localised disease often have good outcomes, while generalised or adult-onset cases may require more extended management.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS