In the March 2007 issue of JSAP, Niessen and others (2007) reported on a case of generalised lymphadenomegaly associated with methimazole treatment, in a hyperthyroid cat. The owner of the cat, which had been presented for routine vaccination, reported a 3-month history of intermittent vomiting and diar- rhoea, and possible polydipsia, polyphagia and concurrent weight loss. On physical examination, the presence of a small thyroid nodule was palpated. Total T4 and free T4 measurement confirmed the diagnosis of hyperthyroidism, and methimazole was prescribed at a total dose of 5 mg twice daily. Within the next two weeks the cat became lethargic and anorectic, and suffered occasional vomiting and bilateral epiphora.