CLINICAL FINDINGS AND INVESTIGATIONS: A 14-year-old female neutered domestic shorthair cat was referred for investigation of progressive hair loss, muscle wasting and hind limb weakness. Diabetes mellitus had been diagnosed 8 months earlier and was well controlled. Abnormalities on serum biochemistry included persistent mild azotaemia, hypochloridaemia, hypokalaemia, metabolic alkalosis and elevated creatine kinase. Physical examination revealed a pot-bellied appearance, with muscle wasting, marked thinning and fragility of the skin, bilaterally symmetrical alopecia, a gallop rhythm and systolic hypertension (173 mmHg). A large, lobulated left adrenal mass was identified using abdominal ultrasound. CONFIRMATION OF DIAGNOSIS: Primary hyperaldosteronism was diagnosed based on an elevated plasma aldosterone concentration and normal plasma renin activity. Hyperprogesteronism was confirmed by adrenocorticotrophic hormone stimulation test.
Practical relevance: This is only the second reported case of hyperaldosteronism and hyperprogesteronism in the cat. Clinicians should be alert to the possibility of concurrent hyperaldosteronism and hyperprogesteronism in cats with adrenal tumours showing clinical signs referable to both conditions. The putative mechanism is either increased secretion of aldosterone and progesterone from neoplastic cells of the zona glomerulosa and fasciculata/reticularis, respectively, or increased production of progesterone, as an intermediate in the synthesis of aldosterone, from neoplastic cells of the zona glomerulosa alone.