House of Education: Gastric ulcers in Icelandic horses

House of Education: gastric ulcers in Icelandic horses by Nanna Luthersson

On Tuesday Nanna Luthersson presented the findings of her research concerning gastric ulcers in Icelandic horses. According to her, Icelandic horses are a bigger challenge to read than other breeds, because they are more stoic and will not easily show any discomfort. Where other horses will show resistance when girding, are not willing to move or show negative behaviour and problems when eating, Icelandic horses will only stop eating when it’s almost too late to help them.

The main risk factor for gastric ulcers seems to be nutrition; whether it is the amount or the interval, like no food for more than 5 hours.
Many studies focus on thoroughbreds were a staggering 80% suffer from ulcers as stress and workload (working/training for more than 4 days a week) seem to be important risk factors. But studies on the Icelandic horse were hardly available as the scope equipment, needed for research, is very expensive and not even available until recently.

Nanna, an equine veterinarian, supervised a study in Iceland about the prevalence of gastric ulcers in young Icelandic horses, which showed that on average almost half of the horses in the research were suffering from ulcers. Not just the domestic horses but surprisingly also the feral ones living outside year-round. When these feral young horses were examined after 8 weeks of training the ulcers dropped significantly. Especially with the ones living in a stable instead of outside. The difference with their roaming days as feral horses was that they got fed on a regular basis and were given shelter. Conclusion is that the amount of forage (>1,5% of the horses’ body weight, on average 6 kg) and the feeding times (>3 at least) was beneficial. Being in a stable also helped: being outside in rain stopped horses from eating as they preferred to stand with their hind towards the wind.

Research amongst Icelandic riding horses showed that prolonged periods of fasting had a negative effect, especially in summer when they tend to gain too much weight and were put in paddocks  Increase in workload without days off in between workdays also had a negative effect on the prevalence of ulcers with this group.
Another surprising result was that next to work and the amount of food they received, there was also an increase in ulcers with geldings versus mares and stallions.

Conclusions which can be drawn according to Nanna Luthersson:

human interference / management is not always negative.
Nature can have a negative influence on health and welfare.
Ulcers can be acceptable for short periods of time but not in horses who are asked to work.

Ulcers might be avoided by:

Forage management (amount so > 1,5 % BW so around 6 kg per 350kg horse at short intervals).
Avoidance of fasting periods (> 5 hours without food).
Feeding in autumn and winter because than grass is not enough.

The House of Education is where you can expend your knowledge about Icelandic horses. You can find all the interesting guests here.