ADRENOCORTICAL CARCINOMA IN A 12-YEAR-OLD MARE

A 12-year-old Dutch warmblood mare was examined because it had suffere d colic intermittently for a few years and had lost weight in the prev ious two months. Palpation per rectum revealed a large firm mass in th e left sublumbar region; the mass was classified post mortem as an adr enocortical carcinoma. The basal plasma cortisol concentration (at 10. 00) of the mare was 94 nmol/litre, within the normal range. As in anot her case of adrenocortical neoplasm, a functional tumour could not be demonstrated. Only one of the 21 horses with a neoplasm of the pituita ry-adrenocortical axis examined by the authors, had the tumour in the adrenal gland.