Validation of Ultrasonography for Assessment of Gastric Emptying Time in Healthy Cats by Radionuclide Scintigraphy

BACKGROUND: The prevalence of gastric emptying (GE) disorders in cats is unknown due to lack of clinically applicable diagnostic tests. OBJECTIVES: The principal aim of this study was to assess correlation between scintigraphic and ultrasonographic measurements of GE time (GET) in healthy cats. Additionally, variability of ultrasonographic GET, and correlation between scintigraphy and ultrasonographic parameters of gastric motility were evaluated. ANIMALS: Eight healthy domestic shorthair cats. METHODS: Prospective study. Scintigraphic GET was determined using a solid test meal containing 4 mCi (99m)Tc‐mebrofenin. Each cat had 3 separate ultrasonographic assessments of GE, performed independent of scintigraphic assessment, after solid test meal consumption. The motility index (MI) of antral contractions was plotted against time and time for each fraction of the area under the MI curve determined. Ultrasonographic GET and MI were correlated to scintigraphic GET. RESULTS: Scintigraphic GET (mean ± SD) for 25, 50, and 75% GE was 103 ± 32 minutes, 196 ± 45 minutes, and 288 ± 62 minutes, whereas sonographic GET for 25, 50, and 75% GE was 106 ± 13 minutes, 203 ± 19 minutes, and 305 ± 27 minutes. There was good correlation between scintigraphic and sonographic GET (r = 0.72–0.82) at 45–90% fractional GE and between scintigraphic GET and time of corresponding MI curve fraction (r = 0.78–0.86) at 40–90% fraction of the MI curve. There was moderate intraindividual variability for sonographic GET and MI curve fraction times as well as significant variation among individuals. CONCLUSIONS AND CLINICAL IMPORTANCE: Ultrasonography is a valid alternative to scintigraphy for assessment of solid‐phase GE and allows assessment of postprandial gastric motility in healthy cats

Variability associated with repeated measurements of gastrointestinal tract motility in dogs obtained by use of a wireless motility capsule system and scintigraphy

Objective - To compare repeatability of measurements of gastrointestinal tract motility in healthy dogs obtained by use of a wireless motility capsule (WMC) and scintigraphy. Animals - 6 healthy adult dogs (mean ± SD body weight, 21.5 ± 1.8 kg). Procedures - A radiolabeled test meal was offered immediately after oral administration of a WMC. Serial static scintigraphic abdominal images were acquired for 270 minutes. A dedicated remote receiver was used for data collection from the WMC until the WMC was expelled in the feces. Each dog was evaluated 3 times at intervals of 1 to 2 weeks. Results - Mean gastric emptying half-time measured by use of scintigraphy (T1/2-GES) for each dog ranged from 99.9 to 181.2 minutes. Mean gastric emptying time (GET) measured by use of the WMC (GET-WMC) in each dog ranged from 385.3 to 669.7 minutes. Mean coefficient of variation was 11.8% for T1/2-GES and 7.8% for GET-WMC. The intraclass correlation coefficient was 69% for T 1/2-GES and 71% for GET-WMC. Results for a nested analysis of covariance suggested that both methods were comparable for the evaluation of gastric emptying. Conclusions and Clinical Relevance - Scintigraphy and a WMC system had similar variation for assessment of gastric emptying. Moderate intraindividual variability was detected for both methods and must be considered when interpreting test results for individual dogs. Repeatability of measurements obtained by use of the WMC was equivalent to that obtained by use of scintigraphy. The WMC system offers a nonradioactive, user-friendly method for assessment of gastric emptying in dogs

Assessment of the relationship between body weight and gastrointestinal transit times measured by use of a wireless motility capsule system in dogs

Objective - To assess the relationship between body weight and gastrointestinal transit times measured by use of a wireless motility capsule (WMC) system in healthy dogs. Animals - 31 healthy adult dogs that weighed between 19.6 and 81.2 kg. Procedures - Food was withheld overnight. The following morning, a WMC was orally administered to each dog, and each dog was then fed a test meal that provided a fourth of the daily energy requirements. A vest was fitted on each dog to hold a receiver that collected and stored data from the WMC. Measurements were obtained with each dog in its home environment. Regression analysis was used to assess the relationship between body weight and gastrointestinal transit times. Results - Gastric emptying time (GET) ranged from 405 to 897 minutes, small bowel transit time (SBTT) ranged from 96 to 224 minutes, large bowel transit time (LBTT) ranged from 427 to 2,573 minutes, and total transit time (TTT) ranged from 1,294 to 3,443 minutes. There was no positive relationship between body weight and gastrointestinal transit times. A nonlinear inverse relationship between body weight and GET and between body weight and SBTT best fit the data. The LBTT could not be explained by this model and likely influenced the poor fit for the TTT. Conclusions and Clinical Relevance - A positive relationship did not exist between body weight and gastrointestinal transit times. Dogs with the lowest body weight of the cohort appeared to have longer gastric and small intestinal transit times than did large- and giantbreed dogs