[Ultrasonographic findings of the stomach in warmblood horses at different filling states].

Subject and aim: The aim of the study was to clarify to what extent the sonographic representation of the stomach changes depending on its filling state.

Material and methods: In a prospective controlled study, warmblood horses presented for gastroscopy were assessed sonographically. The examinations took place when the horses were fed normally (measurement 1), after 12 hours of food deprivation (measurement 2), after insufflation of air during gastroscopy (measurement 3) and after removal of air from the stomach at the end of the gastroscopy (measurement 4). The following objective parameters were recorded: Number of intercostal spaces (craniocaudal extension) and determination in which intercostal spaces the stomach could be visualized sonographically, maximum dorsal extension of the stomach, distance between skin and stomach wall.

Results: The median number of intercostal spaces in which the stomach could be visualized sonographically was 7.5 (IQR 3.75), 1.0 (IQR 1.0), 7.0 (IQR 2.0) and 2.0 (IQR 1.0) for measurements 1, 2, 3 (n=32) and 4 (n=15), respectively. The differences were significant between measurements 1 and 2 and between measurements 2 and 3. There was no significant difference between measurements 1 and 3. After 12 hours of food deprivation, the stomach size measured by the number of intercostal spaces visualizing the stomach was reduced by 75%. The maximum dorsal expansion of the stomach for measurements 1, 2, 3 (n=32) and 4 (n=15) was a median of 38 cm (IQR 15.25), 13 cm (IQR 6.75), 43 cm (IQR 7.00) and 21 cm (IQR 8.00), respectively. The differences were significant between measurements 1 and 2 and between 2 and 3. Concerning the distance between skin and stomach wall, the following medians were determined for measurements 1, 2, 3 (n=32) and 4 (n=15): 5.8 cm (IQR 2.27), 4.05 cm (IQR 3.05), 4.8 cm (IQR 1.48) and 5.9 cm (IQR 2.90). The only statistically significant difference was observed between measurements 1 and 3.

Conclusions and clinical relevance: The sonographic appearance of the stomach changes according to the state of filling. Parameters that are readily determined sonographically are the craniocaudal and maximum dorsal extension as well as the distance between the skin and the stomach wall.