Working up a neurological case in farm animals is not always an easy task. One of the most useful skills is a sound understanding of the principles of characterising the abnormality and localising the lesion. Successfully mastering this aspect reduces the different possible diagnoses, typically from many to just a handful. For example, the ability to distinguish weakness from ataxia will lead to a completely different set of differentials. Equally, this skill often allows narrowing down the likely aetiology. In particular, whether the patient suffers from an acute condition (like a toxicosis or deficiency) requiring swift treatment for optimal prognosis, or a more chronic disease process where treatment may be less urgent or prognosis more guarded. Many metabolic conditions can present in animals as impaired neurological function, such as D-lactic acidosis in calves1 and drunken lamb or floppy kid syndrome, hypothermia and hypoglycaemia in neonates,2 and hypocalcaemia and hypomagnesaemia in older animals.3 If promptly recognised, early treatment often results in good clinical outcomes. Neurological conditions often have a wider impact than just the individual case presented, including zoonotic concerns such as those surrounding the …