Introduction: The diagnosis of canine hypothyroidism is often challenging and it relies on the combined interpretation of the clinical condition, clinicopathological data and hormonal tests. There are no previous studies in the literature that compare the severity of the clinical condition with the clinicopathological findings of this disease. A previous study involving a group of dogs with experimentally-induced-hypothyroidism showed a progressive reduction, over time, of thyrotropin serum concentration (cTSH)1. In the months and years following the induction of the disease these dogs developed overt clinical signs and clinicopathological alterations. It is therefore conceivable that dogs with spontaneous hypothyroidism with normal cTSH serum concentration may over time develop more severe clinical and pathological alterations. Aim of this study was to evaluate the correlation between the clinical severity of hypothyroid dogs and the clinicopathological findings in a population of dogs with spontaneous hypothyroidism.
Materials and Methods: The patients were divided into two groups based on the clinical score (dogs with few clinical signs vs. dogs with many clinical signs) and in two additional groups based on the cTSH serum concentration (within the reference interval vs. above the reference interval). The clinical score, the clinicopathological findings and the specific hormonal tests were then compared between the different groups.
Results: The results of the study did not show any significant difference between the different groups regarding clinicopathological findings, specific hormonal tests and the clinical score.
Discussion: Based on this study, dogs with hypothyroidism and a cTSH serum concentration within the reference range do not exhibit a more severe clinical condition.