Multiple cranial nerve motor deficits, resembling polyneuritis cranialis, in a cat with hyperthyroidism.

A 14 plus-year-old (exact age unknown) neutered female domestic shorthair cat presented with a 6-day history of rapidly evolving difficulty in eating, dropped jaw, protrusion of the tongue, sialosis, change in voice (meow softer and higher pitched) and mild variable pelvic limb weakness. Salient clinical features were a left thyroid nodule, 2/6 systolic cardiac murmur, poor body condition, hypertension, bilateral retinal haemorrhages and an increased total thyroid hormone level consistent with a diagnosis of hyperthyroidism (HT). Neurological examination disclosed mild generalised weakness, bilateral visual deficits attributable to a hypertensive retinopathy and multiple cranial nerve (CN) motor deficits that included; mandibular paresis (CN V), bilateral external ophthalmoparesis (CNs III, IV, VI), bilateral facial paresis (CN VII), dysphagia (CNs IX, X), dysphonia (CN XI) and symmetrical paresis of the tongue (CN XII).