“We carried out a survey entitled ‘Horse Transport Issues and Management,’ and we found an association between transportation and stomach ulcers,” said Barbara Padalino, DVM, PhD, associate professor of animal science in the Department of Agricultural and Food Sciences at University of Bologna.
The survey findings led Padalino and fellow researchers Sharanne Raidal, BVSc, MVSt, PhD, GradDipEd, FANZCVSc, and Georgina Davis, BVSc, to carry out a two-part study in which they hypothesized that transportation would be associated with ulceration of the squamous cell mucosa (the cell layer covering the front or esophageal region of the equine stomach, which is void of glands) and effects would be more severe in horses fasted beforehand.
In part one, the team observed the effect of overnight fasting and confinement on gastric pH and gastric ulcer scores in 12 mares, using nasogastric tubes to aspirate gastric fluid every two hours. They performed clinical examinations and venous blood collection before and after confinement and also performed gastroscopy directly after and 60 hours after confinement.
In part two, the researchers evaluated effects of transportation on 26 horses, shipped 880 km (546 miles) as two consignments of 13 horses, performing the same protocol for venous blood collection and gastroscopy as used in part one.
Key study findings included:
- Average gastric fluid pH levels were significantly higher (more basic) during transport than during confinement;
- Horses fed alfalfa hay (which is high in calcium and associated with buffering stomach acid) one to six hours before transport had significantly more food retained in their stomachs after transport;
- Gastric squamous ulcer scores were higher for 15 horses after transport, with severe ulceration evident in some horses; and
- Severity of squamous ulceration appeared to be inversely related to the amount of feed retained within the stomach during transport—that is, horses with the least feed in their stomachs had more severe ulcers.
Equine gastric contents typically range from 1.5 to 7 on the 14-point pH scale (in which 0 is most acidic and 14 is most basic), according to the American Association of Equine Practitioners
“Our hypothesis was that pH in the stomach would become lower than normal (during transport),” noted Padalino. “Instead it became higher, reaching almost 7. We were also surprised by the fact that after 12 hours of travel with fasting conditions some horses did not empty their stomach.”
Based on these findings, the team is currently evaluating effects of transportation on gastric motility.