Description
Hyperthyroidism is a common condition typically affecting about 10% of older cats. It is generally straightforward to diagnose and manage with a good to excellent prognosis. Typical clinical signs include weight loss, often in spite of a normal to increased appetite. Other common clinical signs include gastrointestinal signs (vomiting, diarrhoea), behavioural changes (restlessness, irritability, increased vocalisation), polydipsia and coat changes. Most cats with hyperthyroidism have a palpable goitre. Routine lab profiles may reveal mild to moderate elevation of liver enzymes, erythrocytosis and leucocytosis. Thyroid hormone assessment is needed to confirm a diagnosis of hyperthyroidism. Total basal thyroxine (T4) levels are elevated in most cats with hyperthyroidism but further diagnostics, including free T4 and TSH assays, may be needed in some cats to confirm the diagnosis.
Further Reading:
Hyperthyroidism in cats
Thyroid: T4 assay lab test
Thyroid: free T4 assay lab test
RACE Approved Tracking #20-1001424