What is Demodectic mange
Demodectic mange, also known as ‘red mange’, is a skin condition that affects dogs. It's caused by a type of mite called Demodex canis. Demodectic mange is caused by an overgrowth of Demodex mites on dogs' skin. The mites usually are present on the skin of healthy dogs in small numbers, but in some dogs, mite infestation can become severe and cause skin problems. This overgrowth is often due to a weakened immune system, which can occur in young puppies or dogs with underlying health problems.
Demodectic mange can be localised, generalised, or affect the paws. The localised form is most common in puppies. The type that affects the paws can be the most difficult to treat.
Dogs with weaker immune systems are more at risk. This includes dogs that are elderly, very young, or those with other underlying health issues, such as diabetes or cancer.
Demodectic mange is not contagious from dog to humans.
Written by Dr. Mariella Roberts, Veterinary Surgeon, Animal Trust Vets CIC | Published April 2025 | Review date April 2027 | This advice is for UK pets only and is not a replacement for seeing a vet
Demodectic mange symptoms
The symptoms of Demodex mange in dogs can vary depending on the severity of the condition. Some comment symptoms include:
Hair loss, especially around the face, paws, and legs
Redness and inflammation of the skin
Scaly patches or crusty sores
Itching and scratching
Infections of the skin, which can lead to bad odour and discharge
When to contact your vet
Contact your vet if your dog is losing hair and developing bald patches or thinning of the coat, or you otherwise think your dog has mange.
Diagnosis
Mange is usually diagnosed through skin scraping or hair plucking. This is a non-invasive test that involves using a scalpel blade and scraping the skin deep enough for mild irritation or bleeding to be noted (this is necessary since demodex lives deep in the hair follicle) or simply removing hair at the root for assessment. The sample is assessed under the microscope. The presence of any mites is considered a positive result.
In adult dogs (e.g. > 18 months) the condition is more likely to occur due to immunosuppression caused by certain drugs or underlying conditions (e.g. underactive thyroid). Therefore, your vet may want to do further tests (e.g. blood tests, urine samples) to investigate further.
Demodectic mange treatment
In some cases, such as puppies with a small bald patch, no treatment may be necessary, as the condition may resolve on its own over several weeks or months.
Other cases may require anti-parasitic treatment, typically administered as a spot-on or tablet.
If a secondary skin infection is present, an antimicrobial wash may be recommended. In more severe cases, antibiotic tablets may be prescribed, provided there is appropriate evidence to support their use.
In adults, the cause of the immunosuppression should be addressed where possible.
Prevention
Some prescription anti-flea and deworming medications prevent and treat mites. Your vet should be able to prescribe this for you.
Pet owners should:
Regularly check your dog’s skin and brush thoroughly
Feed your dog a good quality diet to maintain a healthy body condition
Outlook
The outlook for localised disease in young dogs is very good, and most recover easily from the disease. Generalised cases in young dogs can take many weeks or even months of treatment, but it is usually possible to control the disease with a good long-term outlook.
The prognosis for adult onset generalised demodicosis is more uncertain, as many of these dogs have an underlying illness. If this illness can be identified and cured, the prognosis for managing the demodicosis is much better. Some cases require long term medication to keep mite numbers controlled. However, because it may be inherited, dogs with demodicosis should not be bred.