Abstract
This study aimed to establish a standard dose and sample collection time for 13C phenylalanine and 13C-Dipeptide breath test in horses. To evaluate dose-dependent effects, healthy horses received 2.5 mg/kg, 5 mg/kg, and 10 mg/kg 13C phenylalanine dissolved in 1 ml/kg distilled water and 1.25 mg/kg, 2.5 mg/kg, and 5 mg/kg 13C dipeptide dissolved in 2 ml/kg distilled water. Tmax was observed during the sample collection time. For 13C phenylalanine, the standard deviation of Cmax at 5 mg/kg was lower than that of 10 mg/kg. For 13C dipeptide, the standard deviation of Tmax was the lowest at 5 mg/kg. This study revealed that an optimal dose for breath tests with 13C phenylalanine and 13C dipeptide may be 5 mg/kg in horses.
