What is ... ?:

With this condition there are skin changes due to a lack of growth hormone (somatotropin). This hormone is secreted by the pituitary gland and is necessary for hair growth and the maintenance of normal elasticity of the skin. Affected dogs have varying degrees of hair loss and darkening of the skin, but are otherwise healthy.

Adrenal sex-hormone dermatosis is a clinically similar syndrome that appears to be due to abnormal sex hormone production by the adrenal glands, causing secondary changes in growth hormone levels.

How is ... inherited?:

A mode of inheritance has not been established; however the disorder is mostly seen in the breeds listed below.

What breeds are affected by ... ?:

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

This condition is more common in male dogs between 1 and 5 years of age, with hair loss usually starting at puberty. Adrenal sex-hormone dermatosis is seen in males and females, either neutered or intact.

Hair loss (called alopecia) is symmetrical over the trunk of the dog and the skin is markedly darker in color due to increased pigmentation. Without treatment, hairlessness and hyperpigmentation will eventually spread over your dog's body except for head and feet. The condition does not affect the health of your dog, only his/her appearance.

How is ... diagnosed?:

There are several possible hormonal causes of hair loss in dogs. Your veterinarian will do tests to determine the cause in your pet.

How is ... treated?:

As mentioned, this condition does not affect the health of your dog, only his/her appearance. It can be treated with growth hormone (GH), but this is expensive and can be difficult to obtain. Treated dogs must be monitored for the development of diabetes mellitus which is a potential side effect of GH therapy. Castration may resolve the condition in male dogs.

Similarly, neutering of affected male or female dogs may help to treat adrenal sex-hormone imbalance. If ineffective, there are medical treatments that may be beneficial (opDDD or mitotane, and ketoconazole).

For the veterinarian:

Other endocrinologic causes of alopecia (hypothyroidism, hyperadrenocorticism) should be ruled out. Assessment of growth hormone or serum insulin-like growth factor (IGF) in response to a growth hormone stimulant such as xylazine or medetomidine is available in some laboratories [check with your diagnostic laboratory].

In adrenal sex-hormone dermatosis, elevations in sex hormone levels are seen post- ACTH stimulation.
Histopathologic changes are non-specific - normal to decreased skin thickness with atrophy of follicles, with or without a loss of elastin fibers.

Breeding advice:

Although little is known about the inheritance of this disorder, it is prudent to avoid breeding affected animals or their close relatives.

FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.

Resources:

Schmeitzel, L., Lothrop, C.D., Rosencrantz, . 1995. Congenital adrenal hyperplasia-like syndrome. In J.D. Bonaguara and R.W. Kirk (eds.) Kirk's Current Veterinary Therapy XII Small Animal Practice. p. 600-604. W.B. Saunders Co., Toronto.

acquired growth hormone deficiency

Growth hormone-responsive dermatosis; adrenal sex hormone responsive dermatosis