Scintigraphic assessment of gastric emptying of canned and dry diets in healthy cats

Abstract

Objective - To characterize factors that affect solid-phase gastric emptying in healthy cats by use of nuclear scintigraphy and to assess differences in emptying patterns of dry and canned diets. Animals - 20 healthy cats. Procedure - 2 groups of 10 cats each were fed dry or canned diet for at least 2 weeks before scintigraphy was done. Diets were labeled with 99mTc-disofenin. After ingestion of labeled meals, scintigraphic images were obtained at 0, 15, 30, 45, and 60 minutes, then every 30 minutes to 6 hours. Gastric emptying scans were obtained 3 times for each cat for each diet, in a complete crossover design. The T90, T50, and T20 (times when 90, 50, and 20% of initial meal activity remained in the stomach, respectively) were derived from gastric emptying curves fit to nonlinear models. A mixed models approach was used for data analysis. Results - Gastric emptying was well described by a nonlinear model. Meal size, water intake, and diet type significantly (P < 0.05) effected gastric emptying. The T90, T50, and T20 increased with meal size, regardless of diet type or water intake. Gastric emptying of a dry diet meal took significantly (P < 0.05) longer than that of an isocaloric meal of canned diet, except when meal size was small. Differences in gastric emptying of dry and canned diets varied with the phase (T90 vs T50 vs T20) of emptying. Conclusion - Water intake, meal size, and diet type significantly influence gastric emptying in healthy cats, and these factors must be considered in analysis of gastric emptying data.