Clinical features and outcome of functional thyroid tumours in 70 dogs

Abstract

OBJECTIVE: To describe the clinical features and outcome of functional thyroid tumours in dogs. MATERIALS AND METHODS: Retrospective multi-institutional study of 70 dogs diagnosed with thyroid mass and concurrent hyperthyroidism. Clinical data regarding presentation, treatment, outcome and functional thyroid status were retrieved. RESULTS: Overall median survival of dogs with functional thyroid tumours was 35.1 months and 1- and 3-year survival rates were 83 and 49%, respectively. Median survival time was 72.6 months for dogs treated with surgical excision and 15.7 months for dogs that did not receive surgery. Of the 50 dogs treated by surgery and for which thyroid status was known following treatment, 64% developed hypothyroidism after surgery. Histopathologically confirmed metastasis was identified in 3% of dogs. CLINICAL SIGNIFICANCE: Dogs with functional thyroid tumours may survive a long time after surgical excision, although post-operative hypothyroidism is common.