Accuracy of localizing radiopaque markers by abdominal radiography and correlation between their gastric emptying rate and that of a canned food in dogs.

OBJECTIVES

To determine accuracy of abdominal radiography in locating radiopaque markers in the gastrointestinal tract and to assess correlation between gastric emptying rate of radiopaque markers and that of canned food.

ANIMALS

17 healthy dogs.

PROCEDURE

Dogs were fed thirty 1.5-mm markers and ten 5-mm markers mixed in sufficient food to meet 25% of their daily caloric intake. They were then euthanatized by administration of an overdose of barbiturate at 1, 2, 5, 8, or 12 hours after eating and the abdomen was radiographed. The stomach, small intestine, and large intestine were then separated and radiographed in isolation. The wet and dry weights of the stomach contents were determined. The apparent and actual locations of the markers and the gastric emptying rates of markers, wet matter, and dry matter were compared, using rank correlation.

RESULTS

All comparisons indicated significant (P < 0.025), high correlation coefficients (> 0.92). The mean difference between the apparent and actual locations of the markers was < 3% for all comparisons. The mean difference between the percentage of small markers and large markers retained in the stomach and that of dry matter was 7.8 (SD, 6.2; range, 0 to 18%) and 11.9 (SD, 12.5; range, 0 to 44%), respectively.

CONCLUSIONS

The gastric emptying and orocolic transit rates of the markers were accurately predicted by abdominal radiography. The gastric emptying rate of the diet and the small markers and, to a lesser extent, the large markers was closely correlated.

CLINICAL RELEVANCE

When fed with a special canned food diet, radiopaque markers can be used to assess the gastric emptying rate of food with sufficient accuracy for clinical purposes.