Stomach ulcers have become a widespread disease in horses. Almost every stable has a horse with a stomach problem. But why is that?
To explain why so many horses have stomach ulcers, we first need to look at the horse's anatomy. Horses have a relatively small stomach. With a capacity of only about 8-15 liters, the stomach can only absorb small amounts of food compared to the horse's body mass. The horse is a continuous eater - in the wild, the horse spends most of the day searching for and eating food. Only small amounts of food are consumed continuously.
The contrast to feeding in the stables
Unfortunately, in many riding stables, too little attention is paid to roughage. Often, horses are only given small portions of hay twice a day. This is far too little for horses that are constant eaters. Far more problematic than the amount of hay are the breaks in feeding that result from too little roughage. Unlike us humans, horses are constant eaters and therefore constantly produce stomach acid, regardless of whether they have eaten anything or not. This unused stomach acid can lead to stomach ulcers in the upper part of the body that is not protected from stomach acid.
That is why roughage is so important!
When chewing roughage, much more saliva is produced than when chewing concentrated feed. Saliva has a kind of "buffering effect" on stomach acid. If too little roughage is eaten or the time between meals is simply too long, the horse's stomach becomes over-acidic, which can cause major problems. So make sure that your horse always has enough roughage freely available. At the same time, however, make sure that your horse does not become too fat, as this is also very harmful.
How do I recognize stomach ulcers in my horse?
The symptoms in horses with stomach ulcers are very varied. Examples can be:
- loss of appetite
- colic
- belt or saddle constraint
- Frequent yawning
- chewing
- teeth grinding
- eating sand or soil
- rideability problems
- Aggressive behavior
It is not uncommon for affected horses to show no abnormalities at all... Be alert and do not take even mild symptoms lightly. If you suspect stomach ulcers, do not hesitate to contact your vet. He can perform a gastroscopy to ensure certainty.
What happens during gastroscopy?
Since almost all of the symptoms mentioned can have other causes, correct diagnosis is essential. A reliable diagnosis can only be made by means of gastroscopy. During gastroscopy, a long tube with a camera that reaches into the stomach is inserted through the horse's nose into the digestive tract. In order to be able to adequately examine the stomach lining, the horse is sedated for the examination and the horses must "starve" beforehand so that the stomach is empty during the examination.
Most gastroscopy procedures are performed in a horse clinic. However, there are also some mobile practices that can perform gastroscopy on site using a mobile device.
How is the stomach structured?
A horse's stomach consists of two parts: the "upper" glandless part and the "lower" glandular part. The stomach entrance is in the glandless part, the stomach exit in the glandular part. Both parts are separated by a border line, the margo plicatus (see photo). The glandular part is covered by a thick layer of mucus (mucosa). This protects the mucous membrane from the aggressive stomach acid.
Different forms of stomach ulcers
stomach ulcers in the glandless part
Unfortunately, the glandless part of the stomach is not well protected from stomach acid and is therefore susceptible to feeding errors. Long breaks in eating or too large amounts of concentrated feed can lead to an excess of stomach acid and the sensitive glandless mucous membrane comes into contact with stomach acid and is attacked. Of course, medication or poisoning can also cause stomach problems.
For a while, only stomach ulcers in the non-glandular part were known. These have already been researched quite well and the causes have been proven by several studies. This is mainly because the endoscopes used for gastroscopy used to only be about 3m long. This meant that the non-glandular part of the stomach could be viewed very well. However, since longer endoscopes have been available (about 3.7m long), it has been found that stomach ulcers can also be found in the glandular part of the stomach.
Where do stomach ulcers in the glandular part of the stomach come from?
Causes in feeding
There are many causes of gastric ulcers in the glandular part of the stomach. One cause of gastric ulcers at the stomach outlet (pylorus) can be incorrect feed. Studies show, for example, that feeding alfalfa chopped cattle, at least in weanlings, can worsen stomach health. [1] , [2] The exact cause is not yet known. It is suspected that it is due to the higher salicylic acid content in the alfalfa or the mechanical irritation caused by the chopped straw. However, further investigations are needed, particularly in older horses.
Stress as a cause
In most horses, stress is suspected to be one of the causes of stomach problems. Each horse must be examined closely, as the causes of stress can be varied. The wrong stable neighbor, housing and/or training conditions, general temperament, transport or even pain can cause stress and stomach problems in horses. [3] However, since horses are very individual in this regard, there is no general recipe for stress-free living. One horse may feel more comfortable in a box, while another horse, as an outdoor freak, is happiest in an open stable.
What can you do?
If a horse suffers from stomach problems, the right management is required. In addition to checking the living conditions (keyword: stress reduction), the feeding should also be checked. Horses with stomach ulcers should ideally be fed a grain-free diet. It is also important to ensure that they are provided with sufficient roughage. We recommend at least 1.5 kg of hay per 100 kg of target body weight per day. The feeding breaks should not last longer than 4 hours to avoid over-acidification.
Little helpers can support
In addition to drug treatment, supplementary feed that buffers the aggressive stomach acid can also help. Feed containing calcium carbonate and magnesium oxide, for example, is suitable here. Magnesium also ensures more calm and composure, which can be particularly useful for nervous and temperamental horses. Ingredients such as pectins or sodium alginates can also help protect the sensitive stomach lining. In combination with the stomach acid, a type of gel is formed that provides a protective lining for the stomach. The "mucosa" is thus supported and the natural barrier function is improved.
Since the intestinal microbiome, i.e. the healthy bacteria in the intestine, can also be affected by the disease, intestinal health should not be ignored. Probiotics can help to bring the intestine back into balance.
[1] Fedtke et al. (2015) Effects of feeding different roughage-based diets on gastric mucosa after weaning in warmblood foals, Pferdeheilkunde 31 (2015) 6, pp. 596-602
[2] Vondran et al. (2016) Effects of two alfalfa preparations with different particle sizes on the gastric mucosa in weanlings: alfalfa chaff versus alfalfa pellets. BMC Vet Res. 2016 Jun 14;12(1):110.
[3] Webinar in cooperation with FS animal health: Dr. Monica Venner (2022) Stomach diseases in horses: There is a lot of new information!
