Gastrointestinal transit times in young and old cats.

Ageing results in a decrease in apparent nutrient digestibility in the gastrointestinal (GI) tract. The aim of this study was to investigate whether the rate of gastric emptying or total GI transit times differed between young (3.0+/-0.9 years) and senior (11.6+/-1. 4 years) cats. Gastric emptying rates were measured using [1-(13)C]octanoic acid and total transit times with chromium oxide. No significant differences (P>0.05) were observed in either the rate of gastric emptying or total transit time between young and senior cats although senior cats exhibited a larger variability in total transit time compared to the younger cats (35.71+/-14.06 and 26. 46+/-5.80 h, respectively). The results of this study indicate that the observed reduction in nutrient digestibility in ageing cats is not due to alterations in the rate of passage of digesta through the GI tract.