ADRENOCORTICAL FUNCTION IN THE DOMESTIC CAT DURING TREATMENT WITH LEVONORGESTREL

Levonorgestrel was administered via a subcutaneous, slow-release silas tic implant to 10 queens. Five other queens served as controls. Their adrenocortical function was assessed by the adrenocorticotrophic hormo ne (ACTH) stimulation test before and after one, two, six and 12 month s of treatment. In addition, the gross anatomy and histology of the ad renal gland were examined post mortem in six of the treated cats. In b oth the control and treated queens the plasma cortisol concentrations (pre and post ACTH) were significantly different (P<0.05) at different times. However, there were no significant differences between the pla sma cortisol concentrations (pre and post ACTH) of the treated and con trol queens. No gross or microscopical abnormalities were visible in t he adrenal glands of the treated queens.