Hyponatraemic encephalopathy in azotaemic neonatal foals: four cases

CASE SERIES: Four neonatal foals were presented, over a 2-year period, (2011-2012) with aimlessly walking, head pressing, 'chewing gum' seizures and ataxia. The neurological lesion was consistent with increased intracranial pressure in all cases. All foals had severe hyponatraemia and azotaemia identified on biochemistry. Hyponatraemia was transient in 3/4 cases, with the foal in the final case requiring long-term sodium supplementation. Three foals survived to hospital discharge; one was euthanased because of anuric renal failure and one of the surviving foals was euthanased with septic osteomyelitis 2 weeks after initial discharge. CONCLUSION: Correction of the sodium deficit resulted in resolution of the neurological signs in these foals; however, azotaemia was slow to resolve, suggesting acute renal failure.