Equine Ulcers: Are They Causing
Your Horse Problems?

Don't think you have to worry about equine ulcers? Does your horse suffer from any of the following??

  • Chronic colic
  • Poor body condition
  • Loss of or poor appetite, especially when grain is involved
  • Poor performance
  • Bad attitude while being handled and/or ridden
  • Generally ill tempered
  • Continually fluctuating body weight

If so, your horse could be suffering from Equine Gastric Ulcer Syndrome, the official term for equine ulcers. This is a very common problem in horses, much more prevalent than many owners realize.

Some reports show as many as 85% of pleasure horses suffer from this problem. Rates for horses with stressful lives, such as show horses or race horses have been reported to have rates higher than 95%.

Ages of Horses Affected

Equine ulcers can affect any age of horse, from newborn foal to geriatric animals. Thankfully, they can be treated by various methods, and management practices can be altered to help prevent them.

Young Foals

The condition in very young foals is known as neonatal gastric ulceration. It is usually accompanied by another severe illness, such as generalized sepsis.

Suckling Foals

In suckling foals, the condition is known as gastroduodenal ulcer disease. This form of ulcers is characterized by ulcer in the upper digestive tract -- usually the lower esophagus, stomach, or upper part of the small intestine.

The cause is unknown, but researchers suspect the problem starts with inflammation in the small intestine. This inflammation causes a back-up of acidic digesta, which then causes ulcers in the stomach and lower esophagus.

It is suspected that a viral or bacterial disease causes the initial problems that lead to equine ulcers in these foals.

Mature Horses

The main form of equine ulcers to affect mature horses is erosion or ulceration of the squamous mucosa.

This means the protective mucous layer of the stomach and digestive tract breaks down and can no longer protect the underlying tissue from the acidic environment. When the underlying tissue is exposed to the acid, the acid eats away at it, much like happens to our skin when we spill acid on it.

Risk Factors

A number of risk factors can predispose a horse to equine ulcers. The most obvious is a stressful lifestyle such as that of a show or race horse. Other factors include housing situations, feeding situations, and temperament of the animal.

Intense Exercise

Intense exercise has been shown to play a major role in the formation of ulcers.

One study of Thoroughbred racehorses showed an ulcer prevalence of 100% in horses actively racing. Horses in race training weren't much better off, as the prevalence in that group was 91%.

A study of endurance horses showed that they had an ulcer prevalence of 67% after races.

The current speculation is that tightened abdominal muscles caused by intense exercise cause acidic digesta to back up into the upper digestive tract and remain there longer than usual.

Electrolyte administration

Surprisingly, it has been found that routine administration of electrolytes, such as is done for endurance horses during races, can cause the formation of equine ulcers.

In a study of 14 horses, those that received 8 hourly doses of commercial electrolytes showed a higher number of ulcers compared to the control group. The horses that received electrolytes also had more severe ulcers than the control group.

Confinement Housing

Confinement housing, particularly in a stall, is another risk factor for developing ulcers. Horses with no prior ulcer history who were moved from a pasture situation to stall confinement showed ulcers after only 7 days!

It has been suggested that these types of housing situations cause ulcers due to:

  • Lack of socialization with other horses
  • Changes in diet composition
  • Decreased meal frequency
  • Decreased grazing time

Temperament of Animal

Temperament is also thought to play some role in ulcer formation, though it is not clear exactly how big of a role it may play.

Nervous horses have been proven to have a higher prevalence of ulcers than their more calm counterparts.

Though we are not sure of the exact reason nervous horses are more prone to ulcers, it is currently suspected that this higher frequency might be caused by the body being under continual stress.

Meal Composition

Meal composition is thought to play a role in equine ulcer formation because of how it affects saliva production.

When a hay meal is fed to a horse, more chewing is required, and therefore more saliva (which is an important buffer for the digestive tract) is produced. If an equal weight of grain replaced the hay meal, only half the amount of saliva would be produced.

Saliva is also more continually passed into the digestive tract with a hay meal, since it takes the horse longer to eat the hay meal than the grain meal. This makes a more stable lower digestive tract, because the acidity of the tract is not able to drop dramatically.

Meal Size

Meal size also plays a role in ulcer formation. Large grain meals produce more acid than an equal weight of hay (and less saliva as mentioned above!). The large grain meal will also empty from the stomach more slowly than small grain meals or hay.

So not only have we created more acid, we've also created a situation where it sits in the stomach for a longer period of time. This is practically screaming to ulcers to make themselves at home...

Meal Frequency

Related to both of the above risk factors, meal frequency also plays a role in ulcer formation.

Horses are one of the few animals that constantly produce gastric acid whether or not there is feed in their stomach. This should not be surprising, since they evolved as animals that continually grazed.

Since there is always acid being produced, if there is not a buffer (like saliva!) from eating many times a day, the acidity in the tract will increase. The longer a horse goes without any food in front of him, the more acidic his digestive tract becomes. Like we've mentioned before, this is practically screaming at ulcers to make themselves at home...

The all too common practice of feeding horses twice daily has been shown to be a contributing factor to ulcers. The best way to prevent this problem is to provide enough forage in those two feedings that the horse goes very little time without forage between meals.

Prevention and Treatment of Equine Ulcers

Eliminating as many risk factors as possible from your horse's life is the best way to prevent ulcers. Obviously, some factors, such as frequent showing or racing cannot be changed. However, other factors such as meal composition and frequency can be changed with small changes to management practices.

If you suspect that your horse has ulcers, there are a few things that can be done.

Some owners choose to have their vet scope the animal to check for ulcers before treatment. However, others choose to just assume the horse has ulcers because of the cost of scoping, as well as the fact that the procedure often misses ulcers lower in the tract, where most ulcers are actually located.

Horses will usually show a great improvement within a few weeks of treatment being started, except in the most severe cases.

Change of Management Practices

Changing management practices is often the easiest and most cost-effective way to not only prevent ulcers, but to treat them as well.

Reducing the acid level in the digestive tract by providing continual forage often goes a long way towards treatment of mild cases of ulcers. Removal of high starch meals (or decreased size and increased frequency) also helps to reduce the acidity.

Commercial Products

Changing management practices may not be enough to take care of more severe cases of ulcers. In these cases, commercial ulcer products are often very helpful in protecting the digestive tract long enough for it to heal.

However, its important to note that management changes will need to be made to minimize the risk of the ulcers returning.

Commercial Prevention Products

For horses with chronic ulcers who are not helped even after treatment with commercial products and all feasible management changes have been made, there are commercial prevention products available.

These products are usually added to the feed on a daily basis to help maintain the pH of the digestive tract.

However, these preventatives can be very costly, so are often a last resort for most horse owners.

Equine ulcers can be a very painful problem for many horses. However, with proper management and treatment they can be eliminated from most horses.

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