Acanthosis nigricans is a skin disease that occurs in dogs. This disorder is characterized by darkened areas of skin, hair loss, inflammation, chronic itching and skin infections. The treatment options vary depending upon whether the condition is hereditary or caused by an underlying medical condition.
When this disorder appears in dachshunds, it is usually inherited from one or both parents, and is called primary acanthosis nigricans. Affected dachshunds usually begin to show symptoms before they are a year old. The skin in the groin or underarm region darkens in color. As the condition progresses, the skin thickens and develops a leathery, rough texture, and the hair falls out in that area of the body. Itching and irritation may also occur.
Although dachshunds are most likely to develop primary acanthosis nigricans, dogs of any breed, age or gender can develop secondary acanthosis nigricans because of obesity, allergies, hormone imbalances or endocrine disorders. The primary form of the disorder is rare, but the secondary form is much more common.
Many dogs with either primary or secondary acanthosis nigricans develop a condition called seborrhea. The skin becomes unpleasant-smelling, flaky and excessively oily. Bacteria and yeast can thrive in this environment, so dogs often develop yeast or bacterial infections. This makes the problem even worse.
Veterinarians can easily diagnose acanthosis nigricans by the physical symptoms and appearance. Several other tests, however, might be used to rule out other conditions. Skin scraping is a procedure in which small particles of skin are examined under a microscope to look for the presence of parasites such as mites that may be causing the irritation. The doctor might also want to do a biopsy, or remove a sample of the affected tissue, and run medical tests on it to check for other diseases.
Primary acanthosis nigricans is incurable. Veterinarians control the symptoms with injections of melatonin, which is a hormone that helps reduce stress. Steroid medications help reduce inflamation, and anti-seborrheic shampoos can be used to control the seborrhea and prevent yeast and bacteria from attacking the skin. Vitamin E and skin creams may also provide relief from the itching and secondary irritation.
Veterinarians treat secondary acanthosis nigricans by addressing the condition that is causing the problem. Dogs that are overweight might need to be placed on a canine weight loss plan. Thyroid medication often helps correct the symptoms in dogs that have endocrine disorders. Vitamin E or steroids may be used to help control the symptoms. The symptoms may take several months to clear up after treatment begins.
For more information, see:
Pet Education.com: Acanthosis Nigricans
Canine Inherited Disorders Database: What is Acanthosis Nigricans?
The Merck Veterinary Manual: Acanthosis Nigricans: Introduction
Healthy Pet U: Acanthosis Nigricans
Animal Planet Dog Health Center: Acanthosis Nigricans