Hyperprogesteronemia associated with Sertoli cell tumor and alopecia in a dog.

Hyperprogesteronemia was found in a dog with alopecia and Sertoli cell tumor. Alopecia began in the lumber areas; the entire coat was dull and dry, and epilated easily. The only laboratory abnormalities were high serum progesterone concentration and incomplete suppression of cortisol after low-dose dexamethasone administration. The hair regrew after castration, and the progesterone concentration decreased toward normal.