Food allergies are one source of skin and coat problems in Toy Fox Terrier and the other major concern is a condition known as demodectic mange. Any breed of dog can develop domodectic mange but it is more common in some breeds than others. The Toy Fox Terrier can develop demodectic mange but with proper care and treatment the condition can be treated and eliminated.

Demodectic mange is not inherited from the mother or father dog in the same way as other genetic conditions. All dogs have some number of the demodectic mange causing mites in their skin. In some dogs, typically puppies less than one year of age, stress on the puppy causes the bodies immune system to fail to function properly and the population of the mange mites skyrockets, leading to the symptoms of mange that include hair loss and dry skin in areas around the eyes, the mouth and the chest and front legs. The good news is that this localized demodectic mange will usually clear itself up once the puppies immune system catches up to its growing body. However older dogs that have some concurrent health condition also can develop this lack of control of the normal mite population, leading to hair loss over the entire body and the almost patchy appearance of the coat. Often owners mistakenly think that demodectic mange is either ringworm or food allergies and treatment is delayed because of this misdiagnosis. Diagnosis is done at the vets by taking a small scraping of skin cells from a local spot showing hair loss, then examining these cells under the microscope to look for the mange mites. This is completely painless to the dog, just like gently scratching the top layer of skin to remove a few cells.

In cases of demodectic mange the vet will usually prescribe specific mange baths or dips that are done one a week over a specific period at the vet's office. Between the dips the dog or puppy will be treated with antibiotics to help the immune system, supplements to the food to help with the nutrition as well as creams to ease any discomfort to the skin and to prevent secondary bacterial infections. In mild cases the owners may be provided with medicated shampoo to bath the dog or puppy at home. Generally in puppies the condition will be fully treated in about six weeks with the puppy developing the necessary immune system reaction to prevent further problems. Skin scrapings are again used to confirm that the mites are no longer present.

When older, adult dogs develop demodectic mange the vet has to find out what has triggered the response or shut down of the immune system in the body. In some cases it is caused by various types of cancers that will need to be treated in addition to the mange.

It is important for owners to know that demodectic mange is only transferred by direct contact from an infected dog to a non-infected dog and is not spread through the environment. In addition only dogs or puppies with compromised immune systems will develop demodectic mange even when exposed or directly in contact with a dog showing the signs.