Severe acid-base and neurological derangements in pregnancy toxaemia

Abstract

Two alpacas presented with inappetance, weight loss and weakness during late-term pregnancy (day 315 and 320 respectively). Lipaemia, hyperglycaemia, volume depletion and severe metabolic acidosis were identified in both animals, with ketonuria confirmed in one alpaca. Both alpacas were treated with intravenous fluids, thiamine and regular insulin, tailored to careful heamatological monitoring. The first alpaca demonstrated signs of systemic inflammation and aborted twin fetuses within 24 hours of admission. Subsequently, the alpaca developed acute signs of central neurological dysfunction, with progressive depression and opisthotonus. Despite further treatment, the patient died peracutely following a tonic-clonic seizure. The second alpaca developed central depression and posterior paraparesis with persistent limb abduction in the cushed position within 48 hours of admission. Abortion was induced and the alpaca slowly recovered full neurological function over 17 days. Severe acid-base derangements with subsequent neurological dysfunction have not been previously reported in states of negative-energy balance in pregnant alpacas. This article discusses the clinical presentation and treatment of pregnancy toxaemia in these animals, as well as the potential pathophysiology of life-threatening neurological complications of ketoacidosis.