Gastric emptying scintigraphy (GES) is used to measure gastric emptying in dogs, but the technique is non-ambulatory and requires ingestion of a radioactive meal. Also, GES does not provide information regarding small and large bowel transit time (SLBTT) and total bowel transit time (TTT). Recently, wireless ambulatory capsule technology, the SmartPillTM GI Monitoring System (SP) was introduced to measure gastrointestinal (GI) pH, pressure and temperature, and provide GE and transit time in humans. The purpose of this study was to compare GES to GE measured by the SP and to evaluate the SP for measurement of SLBTT, and TTT in normal healthy dogs.
Six healthy adult (age: 5 to 8 yrs) dogs (4 F and 2 MC), weighing 26.4 ± 1.7 kg were used in the study. Two weeks prior to starting the study, dogs were acclimated to a standard canned food diet (Beef and Chicken Entrée, Science Diet). To assess GE, SLBTT and TTT, food was withheld at 8:00 PM the evening prior to performing the study. On the morning of the study, each dog consumed the standard meal mixed with 99m TcDisofenn (6 mCi). Once the meal was consumed, the SP was administered orally and an additional small meal of the standard diet (55 gm) was given to facilitate passage of the SP into the stomach. Dogs were place in a cage and the SP wireless data receiver mounted on the cage. Gastrointestinal pH was collected every 5 seconds for 24 hours, along with luminal pressure and temperature until the pill was passed in the feces. After administration of the SP, GES was performed in a standard manner for 4 hours. GE measured by the SP was defined as the time from ingestion to a sudden rise in pH>4 of at least 3 pH units from baseline. The TTT was measured from the time of ingestion of the wireless capsule until there was a drop in temperature or abrupt loss in signal associated with a bowel movement. By subtracting GE time from TTT we calculated SLBTT. Data was presented as mean (SEM). GE measured by SP and GES were analyzed using PROC CORR in SAS.
Over 90% of the data packets were received from the SP during the study period. The pill was recovered from each dog in the study. Mean (SEM) for GE with the SP was 6.34 h (0.94) and GES (T10%) was 4.0 h (0.4). There was a strong correlation (CC=0.7587; P=0.08). Mean SLBTT was 31.74 h (7.40) and mean TTT was 38.35 h (7.78).
The SP represents a novel non-scintigraphic method for assessing GE in dogs and correlates well with GES. The GE measured by the SP suggests that it empties near the end of emptying of a solid meal. Also, the SP provides information regarding SLBTT and TTT. The SmartPillTM represents a novel, ambulatory, non-radioactive method to measure GE, SLBTT, and TTT and may be helpful in determining delayed GE and alterations in bowel motility.