-Preventing stomach ulcers-
As big and strong as our lovely equine companions may be, their performance and health is easily diminished due to minor malfunctions and diseases of the digestive tract. Next to well-known problems of the hindgut, such as colic or enteritis, the foregut, and in particular the stomach, is also very prone to upset with potential detrimental consequences. The most commonly seen stomach problem is gastric ulceration, which can cause severe discomfort and drastically reduce performance and overall wellbeing of the horse. Ulcers can develop for various reasons resulting in a compromised protective system allowing the acidic fluids that are present in the stomach to cause severe irritation and lesions. Modern management practices often challenge the horse’s natural feeding behavior leading to a high prevalence of gastric ulcers, especially in performance animals. Research shows that Thoroughbred racehorses are highly affected, as well as Standardbreds, 3-day eventers, endurance horses and other show horses. Because feeding practices play a big role in the development of ulcers, proper nutritional management is vital to prevent this painful condition.
THE EQUINE STOMACH
In comparison with other animals the horse’s stomach is fairly small, which explains why nasogastric intubation is often important to prevent rupture due to digestive fluid build-up during a colic episode. The stomach can be divided into 2 regions which are the non-glandular squamous (upper part) and the glandular (lower part) section. In order to initiate digestion of incoming food, the stomach secretes high amounts of gastric acid from the glandular region. Additionally, to protect itself from the corrosive actions of the acid this region also secretes mucus and bicarbonate which will coat the stomach lining.
Given the size of a horse’s stomach they are clearly not meant to handle large portions of food but are rather natural “trickle feeders”, which means they are meant to graze or eat smaller portions of feed continuously throughout the day. This is further supported by the fact that the equine stomach secretes acid 24/7 in order to digest incoming food at all times. These anatomical characteristics are a first clue why the development of gastric ulcers is mostly due to a non-natural feeding pattern in domestic horse management.
RISK FACTORS FOR DEVELOPING ULCERS
Gastric ulcers can develop in various parts of the stomach, however they are most commonly seen in the non-glandular region as it is less protected by mucus compared to the glandular region. Because natural feeding behavior of many domestic horses is often replaced by meal feeding (2-3x/day), the stomach is exposed to acid without having to digest food for many hours of the day, making the wall lining more susceptible to irritation.
Naturally, horses are designed to eat and get their necessary nutrients from a high fiber diet (i.e. grasses and hays). These roughage particles will form a “fiber mat” which “floats” on the top of the acidic fluid content in the bottom part of the stomach thereby protecting the lesser protected areas against potential splashes of acid. Furthermore, ingesting a diet high in fiber requires more chewing, increasing saliva production rich in bicarbonate, which forms a good buffer against gastric acid.
In adult horses gastric ulcers are most commonly seen in performance animals due to their intensive management and often frequent exposure to stress. Both physical and environmental stresses such as prolonged stall confinement without ability to interact with other horses and transportation or competition stress have been shown to rapidly increase the development of ulcers. Research also reports that exercise itself increases gastric acid production and in combination with longer periods of fasting, in particular lack of access to roughage, an empty stomach will allow the acid to “splash” upward onto the more sensitive non-glandular part of the stomach during a heavy workout.
Even though stress and exercise increase the risk, it is usually the combination with poor feeding practices that will ultimately determine whether ulcers will develop.
Typically horses in intensive training programs receive large portions of grain in order to meet energy requirements and often have little access to pasture for practical reasons or to prevent “grass bellies”. In many cases horses are restricted from forage all together prior to a competition to reduce excess weight. This lack of the fiber buffering capacity in combination with high amounts of starch entering the stomach provides a perfect environment for ulcers to develop. There is a distinct population of microbes present in the stomach of the horse, which readily ferments incoming food particles, in particular, carbohydrates. Byproducts of this fermentation are volatile fatty acids (VFA’s), which as the name suggests, can contribute to an increase in the acidity of the stomach and cause further irritation.
Another major reason for the development of ulcers is the use of certain non-steroidal anti-inflammatory drugs (NSAIDS), which lower the amount of mucus secreted while increasing acid production, making the stomach wall more sensitive to the acid. Especially ulcers developing in the bottom part of the stomach are typically due to excessive or prolonged NSAID administration.
Depending on the severity of the condition, typical symptoms of horses with ulcers are dullness, poor appetite, poor body condition and coat, decreased performance, behavioral changes, loose feces, grinding teeth, yawning and mild to severe colic-like behavior. However, some horses with gastric ulcers show very little to no symptoms, in particular in the early stages.
In addition to risk factors in adult horses, young horses go through various stressful periods in life during which they are prone to develop ulcers. Foals are very susceptible to gastric ulcers in particular when they cannot nurse regularly due to weakness or diseases. Gastric fluids in foals are very acidic and without protection provided by the buffering capacity of milk, the stomach wall easily becomes irritated. Typical symptoms of foals with gastric ulcers are infrequent nursing due to discomfort, grinding teeth and colic-like symptoms such as frequently laying down and rolling. Another age at which young horses commonly develop ulcers is at the time of weaning. Next to being a highly stressful period, a dramatic change in diet often causes weanlings to go off their feed. All these factors together increase the risk of ulcer formation, which can potentially lead to an undesired growth reduction if not properly managed throughout the weaning process.
When symptoms of ulceration are noted it is important to proceed immediately in making a correct diagnosis via nasogastric endoscopy and start treatment if necessary.
PREVENTATIVE NUTRITIONAL MANAGEMENT
Adequate fiber and fiber quality
To prevent digestive upset and ensure optimal health adequate fiber is needed in the horse’s diet. Continuous access to forage will drastically reduce the risk of ulcer development due to its natural buffering capacity as well as increased saliva production. Therefore pasture turnout on good quality grass or free choice hay is preferred. If this is not possible, for example for horses during show/racing season or for medical
reasons, a minimum of 1-1.5kg per 100kg BW of high quality forage should be provided and is preferably given in frequent smaller portions throughout the day. This will reduce the time the stomach is empty and exposed to acid.
Longer periods of fasting prior to heavy exercise should be avoided to reduce risks of splashing acid during the workout. Access to forage will also ensure the formation of a “fiber mat” which will further protect the sensitive areas of the stomach.
Even though all forages have a potential buffer capacity, high quality forage such as alfalfa has much greater protective characteristics due to higher protein and calcium levels. Furthermore, lower quality, “stemmy” forages such as old hay or straw from bedding could potentially further irritate the stomach lining and large quantities of such roughage should be avoided in animals prone to ulcers.
Reduce grain intake
Because rapid microbial fermentation of starches and sugars lead to dramatic increase in stomach acidity, large amounts of concentrate high in molasses should be avoided in animals prone to gastric ulcers. Replacing these types of sweet feeds with plain grains such as oats or barley may decrease VFA production. To meet nutritional requirements for the equine athlete, always provide high quality hay, which will allow for the grain portion in the diet to be reduced. Low starch, high fiber feeds (e.g. Cavalor® FiberForce, Cavalor® Strucomix Original) are preferred and can be used alone or in combination with higher energy feeds in the performance horse to increase total fiber intake and improve both stomach and overall digestive health. Adding fat (e.g. Cavalor® Oilmega) to a low starch, high fiber feed may also be a safer option when more energy is needed. Preferably feed larger quantities of grain in smaller portions (3-5x/day) to reduce the risk for gastric ulcers.
Even though often forgotten, free access to clean water is important in reducing digestive upset. Adequate water intake may dilute acidic gastric fluids and reduce the risk of ulcers. Water should always be available in the horse’s pasture, stall or paddock and made available after exercise, preferably in combination with forage or a highly digestible mash (e.g. Cavalor® Mash & mix).
In addition to proper feeding management, certain supplements such as Cavalor® Gastro 8 may also help in prevention and treatment of gastric ulcers. The herbal and nutraceutical ingredients in Cavalor® Gastro 8 protect and promote healing of the stomach lining while also stimulating saliva production to help buffer gastric acid. In severe cases when treatment with acid suppression medication is needed Cavalor® Gastro 8 is a good complementary product and will result in a faster healing of ulcers and decrease the chance of recurring ulceration when medication is stopped. Cavalor® Gastro 8 can also be used preventatively in horses when stressful times are anticipated.
Be proactive during stressful events
In anticipation of stressful events, good management can prevent a lot of problems, particularly for horses prone to developing gastric ulcers. Ensuring your horse is in optimal condition and properly fed during training and preparation prior to the show season will provide them with a “buffer” in case of potential stress during transport to and staying on the show grounds. If possible, provide the horse with forage during transport or immediately upon arrival as well as clean water. Be aware that water will probably taste different depending on location. Some owners bring their own water to shows to ensure the horse drinks enough. Different water tastes can be masked by adding flavors, however make sure to adapt your horse prior to competition. At all times, water intake should be closely monitored. Stimulate your horse’s appetite by feeding frequent, good quality hay and a high quality, palatable feed low in molasses (e.g. Cavalor® Perfomix, Cavalor® Superforce, Cavalor® Endurix). Sport horses prone to ulcers should preferentially receive their high energy concentrate mixed with a feed rich in long fibers (e.g. Cavalor® Strucomix Original, Cavalor® FiberForce) or be given a low starch, high fiber feed in combination with a fat source (e.g. Cavalor® Oilmega) for extra energy. Preventative treatment with acid lowering medication or ulcer healing supplements such as Cavalor® Gastro 8 may be beneficial if stress is anticipated, however, proper feeding strategies should be the main focus to reduce the risk of ulcer development.