Canine lymphosarcoma and hypercalcaemia: clinical, laboratory and pathologic evaluation of twenty-four cases

Hypercalcemia and renal failure. Etiology, pathophysiology, diagnosis, and treatment

Hypercalcemia is a frequent disorder of calcium metabolism in dogs and cats. Hypercalcemia-induced alterations in renal function and morphology are linked to many of the clinical manifestations observed in hypercalcemic patients. Since many renal effects induced by hypercalcemia are potentially reversible, early recognition and characterization of the problem facilitates rapid therapeutic intervention.

C cell hyperplasia and carcinoma developing in sheep with experimentally-induced lymphosarcoma

Two cases of C cell hyperplasia and one case of C cell carcinoma of the thyroid glands were bilaterally recognized in 11 sheep with experimentally-induced lymphosarcoma. The serum calcium concentration in the C cell carcinoma case was slightly increased above the normal concentration of around 9 mg per dl. Bilateral C cell hyperplasia also developed in the thyroid lobes of the C cell carcinoma case. Immunohistochemically, hyperplastic C cells and tumour cells were positive for calcitonin, calcitonin gene-related peptide, chromogranin A and neurone-specific enolase. No amyloid deposition nor multiple endocrine neoplasia was demonstrated in any of the cases. Ultrastructurally, many secretory granules were observed in the cytoplasm of neoplastic cells constituting the C cell carcinoma and in the hyperplastic C cells.

Hypercalcemia

Elevated serum calcium occurs relatively uncommonly in dogs and rarely in cats. Hypercalcemia can serve as a marker of disease that enables diagnosis but may also contribute to development of lesions and the clinical signs of disease. Specific clinical signs do not necessarily accompany hypercalcemia, and its presence will frequently be unsuspected. Fortuitous hypercalcemia is often discovered after a review of serum biochemical profile results. This article emphasizes malignancy-associated hypercalcemia and the emergence of cholecalciferol rodenticide toxicity as an important cause of hypercalcemia, as well as its treatment.