WHY ARE GASTRIC ULCERS SO COMMON IN RACEHORSES?

Gabrielle Murray looks into the most common condition most, if not all racehorses have to suffer and does a deep dive into the condition and why it's so prevalent.

Anyone who’s ever had an ulcer will probably be able to tell you just how painful they are. But did you know it is estimated that at least half (and it is possibly much more than that, some suggest it is up to 100%) of racehorses have Equine Gastric Ulcer Syndrome (EGUS)?

But why is it so prevalent? The biggest known risk factor for the disease is diet. To supplement their training regimen, racehorses are usually fed high energy meals (such as grains). Unfortunately, this not only increases the acidity in the stomach, but these meals do not take very long to digest (when compared to forage, such as hay/haylage or grass). Horses need to have food in their stomachs at all times, otherwise the acid in the stomach will basically attack the stomach lining, which can cause ulcers. Thoroughbreds in particular are found to be more susceptible to EGUS, but it is unknown whether this is due to the breed itself or how it is managed (i.e. many TBs are racehorses.)

So what can be done about it? The best way to reduce the risk would be to not feed racehorses grains. But that’s not going to happen. Though there is some evidence that a forage-only diet can work and has been effective on Standardbred harness racers in the US, the UK racing industry is a very different story. Not only would it be very difficult logistically (anybody buying hay/haylage knows just how expensive it can be and getting enough grass especially in winter is a challenge) but it is so ingrained (no pun intended) to feed horses high energy meals that I fear no amount of scientific evidence would convince them otherwise.

What’s the answer? The sad truth is there isn’t one. It’s pretty much accepted that any horse in training (this isn’t limited to the racehorse) has a high chance of getting gastric ulcers. You can’t see them from the outside and most horses show hardly any symptoms. But it is thought that the gastric pain from ulcers limits stride length and oxygen consumption, which as a result affects racing performance. It can also affect behaviour making a horse more “unmanageable”. Therefore, it is not only important from a welfare standpoint but from a performance perspective to raise awareness of this disease.

written by Gabrielle Murray