The ammonia tolerance test in horses

Abstract

Clinically normal horses (n = 8) with ages ranging from 5 to 8 years, were starved for 12 h and their plasma ammonia concentrations were measured. The mean fasting plasma ammonia concentration was 17,8±3,8 µmol l-¹. After dosing ammonium chloride at a dose rate of 0,02 g kg-¹, there was a significant increase in plasma ammonia concentration, with a maximum rise after 20 min (P < 0,05). To investigate the influence of temperature on plasma ammonia concentrations of stored samples, 8 plasma samples were stored at -20°C and 4°C respectively. The plasma ammonia concentrations were measured after 6, 12 and 24 h in each of the stored samples. Plasma ammonia concentrations increased significantly after 12 and 24 h when stored at 4°C (P < 0,05). When plasma was stored at 20°C there was no significant increase from baseline concentrations during 24h (P> 0,05).