PRIMARY HYPERPARATHYROIDISM IN 2 CATS

Primary hyperparathyroidism (PHP) is an infrequently diagnosed disorde r in cats, In this report the signs and symptoms of two cats with hype rcalcaemia due to PHP are described, together with the diagnostic appr oach, results of treatment, and immunohistochemical findings. A 9-year -old and a 13-year-old neutered male domestic shorthair cat were prese nted with signs of lethargy, anorexia, and vomiting, Both cats had per sistent hyper; calcaemia and normo- to hypophosphataemia, Cytological examination of a fine-needle aspiration biopsy sample of a palpable ce rvical mass revealed groups of benign glandular-epithelial cells in on e cat, In the other cat no cervical mass was palpable. In this cat pla sma parathyroid hormone (PTH) levels were measured repeatedly and thes e values exceeded the maximum reference value on two occasions, Follow ing exclusion of other causes of hypercalcaemia both cats were subject ed to neck surgery and in both a solitary parathyroid adenoma was remo ved, The adenomas contained an abundance of PTH, as demonstrated by im munohistochemical techniques, Plasma calcium and phosphate concentrati ons returned to within reference ranges postoperatively. Recovery was uncomplicated and there were no signs of recurrence on follow-up exami nations.