Primary hyperparathyroidism caused by a parathyroid carcinoma in a 16-year-old male neutered cat with concurrent chronic kidney disease.

A 16-year-old domestic shorthaired cat with chronic kidney disease was presented with a subacute history of weakness and anorexia. Severe hypercalcaemia was identified and attributed to a cervical mass, diagnosed as a parathyroid carcinoma after surgery. Renal function, as evaluated by plasma creatinine, initially worsened during hypercalcaemia but fully returned to previously documented values two months post-operatively.