Assessment of the rate of solid-phase gastric emptying in ponies by means of the C-13-octanoic acid breath test: a preliminary study

Abstract

The aim of this study was to assess the feasibility of applying the C-13-octanoic acid breath test for assessment of gastric emptying in ponies by investigating the pattern of C-13 enrichment in breath following the administration of a test meal +/- C-13-octanoic acid. After a 14 h fast, the ponies received either no meal (Test I) or a standardised test meal labelled with 0 mg (Test 11), 125 mg (Test III), 250 mg (Test IV) or 500 mg (Test V) C-13-octanoic acid. For each test (I-V), exhaled breath samples were collected in duplicate at 1 h and immediately before ingestion of the test meal and at frequent intervals thereafter for 12 ll, Breath samples were analysed by continuous flow isotope ratio mass spectrometry, Three indices of breath C-13-enrichment were computed; half dose recovery time (t1/2), gastric emptying coefficient (GEC) and time to peak breath C-13-enrichment t(max), For Tests I and II, the ratio of (CO2)-C-13:(CO2)-C-12 remained stable for the duration of the sampling period. For Tests III, IV and V, an increase in the ratio of (CO2)-C-13:(CO2)-C-12 was detected. The test was reproducible within individuals, and intersubject variation was low, Further validation studies of this noninvasive technique are justified.