Intravenous fluid therapy for the equine patient

General principles of fluid therapy

Intravenous fluid therapy is most often administered to horses in emergency situations to improve cardiac output and tissue oxygenation and correct electrolyte and acid–base disturbances. Initiation of fluid therapy involves evaluation of a horse’s history, clinical examination and laboratory parameters, with consideration to planning, practicality and economics. The general aims of fluid therapy are to restore plasma and fluid deficits, counteract ongoing losses and maintain fluid and electrolyte balance.

Identifying patients requiring fluid therapy

Clinical signs used to evaluate fluid status (Table 1) typically assess both hypovolaemia and dehydration and provide a semiquantitative but crude estimate of a patient’s fluid deficit. A more complete picture of fluid status can be obtained by using clinical pathology parameters such as packed cell volume, total protein, lactate, creatinine concentrations and urine specific gravity (USG). Normal lactate concentrations in adult horses are <2 mmol/l; however, most horses have levels <1 mmol/l. Increases in blood lactate concentration indicate inadequate circulating plasma volume. These parameters can also be used to monitor the response to initial resuscitation, and to help tailor the fluid plan over time. […]