Real-time ultrasonographic evaluation of canine gastric motility in the postprandial state.

Gastric motility is affected by several pathological conditions which may induce upper gastrointestinal clinical symptoms. The pathogenesis of canine gastric motility disorders is poorly understood because of methodological limitations. This study aimed at establishing a simple method for evaluating postprandial gastric motility in dogs. Gastric motility was ultrasonographically assessed in 7 healthy beagles using a technique previously described in humans. The motility index (MI), an indicator of gastric antral motility, was calculated by measuring the area of the gastric antrum in both a contracted and relaxed phase and by counting the number of contractions. The MI was measured every 30 min for 3 hr after feeding and compared with gastric emptying as assessed by a (13)C-octanoic acid breath test. The MI at 30 min had the lowest variability in the 7 dogs (mean SD, 9.77 ± 0.42; coefficient of variance, 4.25%), and a significant correlation was observed with gastric emptying coefficient (R(2)=0.8126, P=0.005) and half-emptying time (R(2)=0.654, P=0.027). When atropine was administered, a significant decrease in the MI at 30 min was observed compared with the control (9.77 ± 0.42 vs. 5.19 ± 0.22, P=0.0003). In conclusion, evaluation of the MI at 30 min is suitable for assessing gastric motility and enables us to assess gastric motility simply in a short time. By using this method, further studies for the pathogenesis of canine gastric motility disorders are warranted.