Dropped jaw as a feature of suspected nutritional encephalopathy in a cat

A 3‐year‐1‐month‐old female neutered domestic shorthair cat was presented for reluctance to jump over 3 months. Neurological and orthopaedic examinations, laboratory tests and cerebrospinal fluid analysis were unremarkable. Magnetic resonance imaging revealed mild bilateral symmetrical intra‐axial changes in the caudal brainstem. The cat deteriorated 1 week later, presenting obtunded with a dropped jaw, facial analgesia and vestibular ataxia. Neuroanatomical localisation was to the brainstem. Ophthalmic examination revealed retinopathy consistent with taurine deficiency. Dietary history indicated long‐term exclusive feeding of cooked chicken and fish. The cat responded well to dietary modification and taurine, thiamine and cobalamin supplementation, with recovery of jaw tone and prehension within 2 months. At the 6‐month follow‐up, the cat was neurologically normal and maintained on a commercial diet. This report describes an uncommon presentation of dropped jaw with concurrent brainstem dysfunction in a cat fed a cooked chicken and fish diet, showing excellent response to dietary modification and supplementation.