Evaluation of various electrolyte replacers for horses

Abstract

The effectiveness and cost of horse electrolyte supplements in horses were investigated. The three products tested were 4 Salts � (Ridley AgriProducts), NaCl (table salt) and Humidimix �(Vetsearch International) and these were fed according to the manufacturers' recommendations. The trial was based on a split plot Latin square design. Four thoroughbred geldings were randomly allocated to one of four treatments (control plus 3 electrolytes). Frusemide (1 mg/kg BW i/m) was used to simulate the fluid and electrolyte loss of moderate exercise in the horses. Blood and urine samples were collected prior to administration of frusemide and at 3, 5 and 24 h post injection. The samples were analysed for Na, Cl, K, Mg and creatinine. The fractional excretion ratio (FER) was calculated to quantify the horse's electrolyte clearance and to determine the time the horses took to eturn to pre-injection levels. For the three electrolyte treatments, the horses returned to pre-frusemide injection levels within 24 h. However, 24 h after the frusemide injection the Mg FER values for the horses receiving no electrolytes were significantly lower than the pre-injection levels. Because the implications of this decrease are unknown it is recommended that horses in moderate work and being fed good quality roughage diets may need to be fed an electrolyte supplement. Given the lack of variability between the electrolyte treatments, the added costs of feeding Humidimix� and 4 Salts� (compared to salt) cannot be justified.