In endurance horses, metabolic disorders subsequent to effort are sometimes associated with neurological problems. This article reports a case of a horse that presented initially with a diaphragmatic flutter that subsequently developed amaurosis, agitation, ataxia and loss of consciousness. Common signs that should be systematically checked during metabolic examinations were found on comparison of this case and three other cases seen during high-level races. The possible causes of these problems are reviewed and include hyperthermia, hypocalcaemia, hyperammonaemia, hyponatreamia and hypoglycaemia. Ancillary tests and treatments that should be instigated are also outlined.