Clinicopathological features and comorbidities of cats with mild, moderate or severe hyperthyroidism: a radioiodine referral population

Abstract

Incidental diagnosis of hyperthyroidism occurs commonly, potentially owing to increased disease screening. Cats with severe hyperthyroidism at referral were more likely to be chronically hyperthyroid with a history of poor stabilisation. This subset of patients was significantly more likely to have cardiac abnormalities. Thyrotoxic cardiomyopathy may ultimately affect patient suitability for curative treatments (radioiodine or thyroidectomy) owing to higher anaesthetic risks and potential for decompensation into congestive heart failure with the stress of travel and hospitalisation. Curative therapy should be considered before the development of severe hyperthyroidism.