HYPERCALCEMIA IN THE DOG - A STUDY OF 40 CASES

Forty dogs referred to the University Department of Clinical Veterinary Medicine, Cambridge for medical and oncological conditions between 1985 and 1990 were found to be hypercalcaemic. In 18 cases the primary or underlying condition was diagnosed as lymphoproliferative disease with multicentric lymphoma occurring most commonly. Ten dogs were suffering from hypoadrenocorticism (Addison's disease) and two had adenocarcinomas of the apocrine glands of the anal sac. In three dogs a clinical diagnosis of renal dysplasia was made, this diagnosis being confirmed at post mortem examination in one dog. In the remaining cases hypercalcaemia was associated with a primary lung tumour, a thymoma, an osteosarcoma with widespread skeletal metastases, primary hyperparathyroidism due to a parathyroid adenoma, chronic panniculitis, iatrogenic hypoadrenocorticism following mitotane therapy (one case each) and, in a further case, no diagnosis was reached. The most common clinical signs were inappetence, polyuria/polydipsia polydipsia, weakness, vomiting, lethargy and depression. As a group, the dogs with lymphoproliferative disease had a significantly higher mean plasma calcium concentration (4.3 +/- 0.7 vs 3.5 +/- 0-4 mmol/litre), a significantly lower mean plasma inorganic phosphate concentration (1.5 +/- 0.5 vs 2.4 +/- 10.9 mmol/litre) and were significantly older (5.5 +/- 2.4 vs 3.3 +/- 1.8 years) than the dogs with hypoadrenocorticism.