Many of the previously described therapy responsive dermatopathies (GH responsive, castration response, Lysodren responsive, melatonin responsive etc) have very similar clinical presentations and perhaps their response to those therapies is non-specific. The pathophysiology of this presentation is somewhat controversial. Certain breeds are predisposed – Pomeranians and Chow Chows.
Unfortunately, such enzyme deficiencies have yet to be demonstrated in-vitro. The condition is thought to be due to a partial deficiency in glucocorticoid synthesis which results in the accumulation of the adrenal sex hormones that are precursors for these steroids. Presentation is similar to the previously described growth hormone (GH) responsive alopecia and it is now thought that although decreased levels of GH may be a contributing factor, these are secondary to the sex hormone imbalance. The clinical signs are symmetrical alopecia and hyperpigmentation on the rump, perineum, caudal thighs, neck, tail and trunk, other areas being generally spared. Adrenal sex hormone imbalance or congenital adrenal hyperplasia-like syndrome is a recently described disorder in dogs.
