Acanthosis nigricans

What is ... ?: 

This is a disorder of hyperpigmentation (an increase of the dark pigment melanin) in the skin. This condition can occur in any breed secondary to other skin disorders, but the inherited primary form is seen almost exclusively in the dachshund.

How is ... inherited?: 

The mode of inheritance has not been established, although autosomal recessive or polygenic inheritance has been proposed.

What does ... mean to your dog & you?: 

The disorder first appears at 3 to 12 months of age. It starts in the underarm region as darkening of the skin, which gradually becomes thickened, leathery, and hairless. Often the groin region is affected, and sometimes the condition spreads to other parts of the body as well.
Commonly there is seborrhea (the skin becomes greasy with a rancid odour) and this sets up a favorable environment for a yeast or bacterial infection to develop.  These conditions usually cause itchiness, and your dog's scratching can cause trauma to the skin and a worsening of the problem.

How is ... diagnosed?: 

Diagnosis is based on the typical appearance of this condition in a young dachshund.

How is ... treated?: 

Primary acanthosis nigricans can not be cured, but it can be successfully managed. Your veterinarian will advise you on ways to achieve this, through such measures as regular bathing with anti-seborrheic shampoos, and through appropriate treatment of any secondary conditions that develop.
For the veterinarian: Topical therapy, oral vitamin E, corticosteroids, and injectable melatonin have all been used with some success.

For the veterinarian: 

Malassezia dermatitis and staphylococcal pyoderma are common secondary invaders with acanthosis nigricans.

Breeding advice: 

Preferably, affected dachshunds should not be used for breeding.


Scott, D.W., Miller, W.H., Griffin, C.E. 1995. Muller and Kirk's Small Animal Dermatology. pp. 782-4.  W.B. Saunders Co., Toronto.

What breeds are affected by ... ?