Studies on Gastric Emptying in Ponies

Wyse, Catherine Anne (1999) Studies on Gastric Emptying in Ponies. Master of Veterinary Science thesis, University of Glasgow.

Abstract

Disordered gastric emptying has been associated with several medical disorders in the horse, but little is known about the physiology of equine gastric emptying, largely due to the inefficiency of the methods available for its assessment. The 13C-octanoic acid breath test (13C-OBT) was recently developed as a non-invasive method for assessment of gastric emptying in man and the aim of this study was to investigate the feasibility of applying this test for assessment of gastric emptying in ponies. The 13C-OBT involves the ingestion of a 13C-octanoic acid substrate which is absorbed rapidly in the duodenum, and is excreted in the breath as 13CO2. Because gastric emptying is the rate-limiting step in the digestion and metabolism of octanoic acid, the rate of excretion of 13CO2 is proportional to the rate of gastric emptying. An initial study established that the basal level of breath 13CO2 excretion in three healthy ponies was low, and remained stable over 12 hours. There was no significant change in the pattern of 13002 excretion following ingestion of an unlabelled test meal in three ponies. These findings confirmed the potential for enrichment of breath 13CO2 excretion in the pony, by administration of a 13C-labelled substrate. The test protocol was then repeated on three ponies following ingestion of test meals enriched with 125mg (n=3), 250mg (n=6) and 500mg (n=3) 13C-octanoic acid. All doses produced a significant increase in the levels of breath 13C, and this increase was proportional to the dose administered. The test was reproducible within individuals and inter-subject variation was low. The duration and frequency of breath sampling in these studies was lengthy, and the possibility of simplifying the protocol was investigated by recalculating the breath test parameters while progressively omitting data points. This investigation showed that in the healthy pony the test duration could be shortened to 6 hours, but the sampling frequency could not be altered without affecting the accuracy of the test. The ingestion of energy dense meals has been shown to cause delayed gastric emptying of solids in man, and in the horse. A second aim of this study was to investigate the effect of increasing test meal energy density on the parameters of the 13C-OBT in healthy ponies. There was a significant difference in the breath test parameters following ingestion of high and intermediate energy density meals, when compared with a low energy density meal, but no difference between intermediate and high energy density meals. These findings indicated that the ingestion of an energy enriched test meal was associated with delayed gastric emptying, but this delay was not directly proportion to the calorific load ingested. The results of these studies suggest that the 13C-OBT is a non-invasive and reproducible method for the assessment of gastric emptying in the horse, and further validation is justified.

• Item Type: Thesis (Master of Veterinary Science)
• Qualification Level: Masters
• Additional Information: Adviser: Sandy Love
• Keywords: Veterinary science, Animal sciences
• Date of Award: 1999
• Depositing User: Enlighten Team
• Unique ID: glathesis:1999-75392
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Nov 2019 20:18
• Last Modified: 19 Nov 2019 20:18
• URI: https://theses.gla.ac.uk/id/eprint/75392