All dogs can become afflicted with bacterial dermatitis, ringworm or mange, but according to the Canine Inherited Disorders Database (CIDD), Great Danes are prone to the following inherited skin diseases: acral lick dermatitis, demodicosis, hypothyroidism, histiocytoma and zinc-responsive dermatosis.
Many healthy dogs carry small numbers of the Demodex canis mite but an inherited immune defect in Great Danes causes this mite to multiply, says the CIDD, and can cause localized spots of red, scaly skin and hair loss or progress into the more serious generalized demodicosis. Localized demodicosis is seen in Great Dane puppies who are 3 to 6 months old, usually on the face or front legs. This usually clears up on its own.
Generalized demodicosis becomes apparent from 3 to 12 months and spreads over the entire dog. Secondary infections occur and resistant bacteria can complicate treatment. Some dogs develop the patches on their feet, which easily become infected and painful. Demodicosis is a skin disease that will not spread to other pets or people.
Hypothyroidism is common in Great Danes. It may be a congenital or an acquired condition. The congenital condition can be identified by the stunted growth of Great Dane puppies, states CIDD. They also develop other abnormalities because of the lack of thyroid hormones, and severely affected puppies die before weaning. Congenital hypothyroidism can be treated if it's caught before the dog ages past 3 to 4 months. Acquired hypothyroidism becomes evident in middle-aged dogs, about 4 to 10 years of age. Changes in the coat of the Great Dane are the first clues–symmetrical hair loss, dry hair or greasy hair. Your Great Dane will need thyroid replacement hormones for the rest of its life.
Histiocytomas are benign tumors that grow on the ears, head or limbs of Great Danes, most often when they are younger than 2. This skin disease doesn't pose a health risk unless the tumors are itchy and your Great Dane chews or worries at them. Most histiocytomas disappear on their own and they can also be removed by traditional surgery or by being frozen off.
Great Danes, along with some other dog breeds, seem to have a higher requirement for zinc, states CIDD. This skin disease usually occurs around puberty and appears as crusting, reddening and scaling around the eyes and muzzle. The patches can also occur on the footpads and around the anus and vulva. Hair loss also occurs and the skin is itchy in about half the cases. Zinc-responsive dermatosis is easily treated with zinc supplements.
Acral Lick Dermatitis
Acral lick dermatitis is also known as lick granulomas. Great Danes are among the dog breeds commonly afflicted with this skin disease. Dogs will continually lick at a leg area until it becomes open, raw and weeping. It can become ulcerated and vulnerable to secondary infections. It is believed that intelligent breeds can become easily bored and frustrated, contributing to acral lick dermatitis. Other theories about its cause include inherited sensory nerve disorder and obsessive-compulsive disorder. Lick granulomas are difficult to treat. Your veterinarian may prescribe anti-anxiety or antidepressant medications, help you to enrich your dog's environment or try behavior modification techniques.