Gastroenterology

Metoclopramide May Treat Delayed Gastric Emptying

By Adam Marcus

Equine veterinarians tempted to use metoclopramide to treat delayed gastric emptying may be put off by the potential side effects, which include colic, restlessness and aggression. But a recent study suggests long-term oral treatment with the drug may be a safe and effective therapy for animals with delayed emptying and chronic gastric dilation.

“Metoclopramide in horses is a controversial topic because it does have great effects on gastrointestinal motility but also has strong side effects in some horses after IV use, even in low dosages,” said Farina Bätjer, DVM, DECEIM, an equine veterinarian at the Equine Clinic Destedt, who led the study.

Metoclopramide acts as an antagonist of at least 3 receptor pathways with effects on both the gastric and central nervous systems: central dopaminergic receptors, peripheral 5-HT3 receptors and 5-HT4 receptors.

In the new study, Dr. Bätjer and her colleagues looked at data from the medical records of 42 horses treated for gastric emptying conditions treated with metoclopramide between January 2011 and April 2023. They also surveyed the animals’ owners to identify clinical improvement in the horses, as well as any clinical issues and side effects linked to the treatment.

Many With Recurrent Colic
Roughly half (51.7%) of the horses (mean age, 13.2 years) that received metoclopramide were experiencing recurrent colic, and 41.4% had signs of poor performance as initial presenting complaints. The mean dose of metoclopramide administered was 0.15 ± 0.03 mg/kg orally every 12 hours (max: 0.22). The mean duration of therapy at the time of data collection was 31.9 months.

Of the 29 owners who responded to the survey, nearly three-fourths said their animals had improved clinically by at least 50%, and half said they’d observed at least 75% improvement in symptoms, according to the researchers. Only 1 of the 42 horses showed side effects (colic) linked to the treatment.

One-third of the cases were examined by ultrasound, and metoclopramide did not appear to shrink the animals’ stomach. In 8 cases, the horses were euthanized because of chronic gastric dilation (median survival time, 22 months).

Dr. Bätjer said her group sought to study the long-term effects of metoclopramide because “most cases of gastric dilatation, we believe and have experienced so far, are irreversible and these horses need medical treatment permanently to live happily without clinical symptoms. That is why some horses received the medication for 3 years or longer.”

However, she noted, the average time to improvement in symptoms was around 2 weeks, “which tells us that the reason for improvement could have been the metoclopramide together with feeding changes.”

Dr. Bätjer said an advantage of metoclopramide over other drugs, such as bethanechol, is that it both induces gastric motility and restores coordination of motility.

“In our practice we use metoclopramide as a standard treatment already in cases of gastric dilatation, impactions and delayed gastric emptying,” she said. “The findings of our study favor our treatment. In future research we want to find out more about possible feed and managing adaptations that could benefit diseased horses.” MeV

For more information:
Bätjer F, Bäuerlein V, Vervuert I, et al. Outcome of horses with gastric dilation and delayed emptying treated with oral metoclopramide. Equine Vet Educ. 2025 Feb. 14.
https://beva.onlinelibrary.wiley.com/doi/10.1111/eve.14124