Demodex mites in dogs

isolated dog

Overview

Demodex mites live on all dogs in small numbers. Most of the time they don’t cause a problem and you won’t even know they’re there. If a dog becomes immunosuppressed (loses the ability to fight off infections and parasites) demodex mites are able to multiply and invade the skin. This is most likely to happen to dogs less than a year old and dogs with other illnesses.

Demodex causes red, crusty skin, hair loss and a scaly coat, worst around the eyes and feet. Demodex is normally quite simple to diagnose but treatment can be challenging.

Call your vet for an appointment if your dog has signs of a skin problem. If your dog has had demodex previously, you will need to keep checking for signs of it returning.

Demodex explained

Demodex mites live on all dogs in small numbers. Most of the time they don’t cause a problem and you won’t even know they’re there. If a dog becomes immunosuppressed (loses the ability to fight off infections and parasites) demodex mites are able to breed and invade the skin. This is most likely to happen to dogs less than a year old and dogs with other illnesses.

Demodex mites live in and around hair roots so when mite numbers increase they often cause hair loss (alopecia).

Demodex isn’t contagious.

Symptoms

  • Dry, scaly, wrinkly skin around the eyes and feet (occasionally over the whole body)
  • Hair loss (alopecia)
  • Red, crusty, skin
  • Greasy coat
  • Pus filled spots
  • Darkening of the skin
  • A mild itch
  • Bacterial infections (more itchy)
  • Usually a disease of young dogs (less than a year old).

When to contact your vet

Contact your vet for an appointment if you notice any of the symptoms above.

You know your dog if they don’t have the symptoms listed above but you are still concerned it’s always best to contact your vet.

Diagnosis

Hair loss, scaling and a greasy coat in a young dog, especially in particular breeds like Staffordshire Bull Terriers, point towards demodex. To confirm a diagnosis your vet may take a skin scraping, (a small sample of the skin) and look for the tiny mites under a microscope.

Treatment

Treatment for demodex may include:

Insecticides

  • Insecticide treatment to reduce mite numbers will be needed. This is usually available as a ‘spot-on’, tablet or shampoo.

Other treatments

  • Antibiotics aren’t always needed but may be necessary if your dog has also developed a skin infection.
  • If your dog’s skin is itchy or very greasy, your vet may advise a soothing and de-greasing shampoo.

Outlook and ongoing care

If your dog has demodex make sure you follow all treatment instructions from your vet. If you stop treating too soon, symptoms are likely to return.

Demodex can take several weeks to fully resolve. It’s likely your dog will respond well to treatment but if they have an underlying illness demodex may come back again in the future. Keep checking your dog’s coat for any signs that demodex is returning.

Cost

You can’t predict whether your dog will suffer from demodex or not and treatment can become expensive. Consider insuring your dog as soon as you get them, before any signs of illness start. This will ensure you have all the support you need to care for them.

It’s also very important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your dog. There are often several treatment options so if one doesn’t work for you and your pet then the vet may be able to offer another.

Published: February 2019

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Written by vets and vet nurses

Illustrations by Samantha Elmhurst