Influence of Diet and Nutrition on Equine Gastric Ulcers, Essay Example

Dietary and Nutritional Implications on Equine Gastric Ulcer Syndrome (EGUS)

Equine Gastric Ulcer Syndrome (EGUS) is a condition in horses, mostly found in race horses, characterized by the development of ulcers in the glandular (distal) stomach, squamous (proximal) stomach, proximal duodenum and terminal esophagus. Despite the fact that this condition is most common in high performance horses, it can be found in all ages and breed of horses. Current EGUS management strategies focus on creating a conducive environment for ulcer healing by increasing the stomach pH as well as blocking gastric acid secretion. There are a number of pharmacologic treatment techniques that can be effectively applied. However, these treatments are costly and necessitate employing other cost effective measures. Dietary and nutritional management has been found to be a vital role in the development and healing of EGUS in horses. As such, it can be used to complement pharmacological treatment and enhance the ulcer healing process. This paper focuses on the implications of nutritional and dietary aspects on the development and healing of EGUS in horses.

Anatomy and the Secretion of Gastric Acid

Because horses have compound stomachs, they are naturally predisposed to gastric ulcers. The areas lined with non-glandular stratified squamous epithelia account for 80% of all gastric ulcer occurrences (Reese & Andrews, 2009). This is the distal third of the stomach, located near the distal two-thirds of the stomach where Hydrochloric acid and pepsinogen is produced for digestion. It is also the area that is responsible for producing bicarbonate and mucus for protective functions. The horse’s stomach constantly excretes HCL and as such is predisposed to low pH levels associated with the development of gastric ulcers.

Prevalence

High Performance Horses

Gastric ulcers has been found to be common in all horse breeds. A study revealed over half (52%) of all horses between one and 24 years depict symptoms of gastric ulcers regardless of the breed. The prevalence is even higher in high performance horses. A study on Hong Kong’s through bred horse, both retired and active, depicted a 66% prevalence rate of gastric ulcers. However, when the research considered only the active thoroughbreds, the prevalence rate rose to 80%.

Gastric ulcers prevalence rate appears to be the same across the board as these results are confirmed by a study conducted by The Equine Gastric Cancer Council. The study depicts that 80% to 90 % of horses in high performance training have been diagnosed with gastric ulcers, with most of these ulcers appearing in fundic area of the stomach.

Foals

Foals have also been found to be susceptible to gastric ulcers. However, consequences are considerably magnified in foals. 25% to 51% of foals are diagnosed with gastric ulcers. Gastric ulcers can cause prolonged indisposition and even death. Foals have been found to have considerable capacity in producing gastric acid. Research has found that 1 week old foals can have stomach pH readings as low as 2, while two day old foals can have as lows 4 (Sprayberry & Robinson, 2014). This is despite the fact that at birth, the equine gastric epithelium is considerably thin. If deprived of proper nutrition during the first four weeks after birth, the continual production of strong gastric acid leads to the development of severe ulcers and even stomach ruptures in extremely severe cases. Foals suffering from gastric ulcers depict the following symptoms:

• intermittent nursing
• poor appetite
• colic
• esophagitis
• gastric outflow obstruction
• poor body condition
• diarrhea
• bruxism
• ptylism
• rupture (perforation)
• peritonitis(Sprayberry & Robinson, 2014)

Causes

Gastric ulcer result when damage is inflicted on the gastric lining. This damage can occur in either if three ways;

• Aggressive Factors: these are factors that work against the gastric lining by corroding it. When these factors overpower the gastric lining, gastric ulcers form. These factors include gastric acid, organic acids, bile and pepsin.
• Overpowering Defensive Factors: there are a number of processes that are in place to help protect against gastric ulcers occurring. There are instances when the production of these factors overpowers the gastric mucosa, ulcers develop. They include mucus and bicarbonate.
• Lacking Defenses; the squamous mucosa may lack the appropriate defenses and may lead to the development of gastric ulcers(Geor, Harris, & Coenen, 2013).

Table 1: Physiologic factors affecting ulcer development

Risk factors

Intense Exercise

During intense exercise, a horse body initiates the production on hormones that are responsible for triggering the production of acid, gastric acid, in the stomach. Intense exercise tends to increase the production of serum gastrin. An increase in serum gastrin triggers an increase in the secretion of hydrochloric acid, lowering pH in the stomach (Huntington & Myers, 2004). During these intense exercises, the non-glandular areas of the esophagus and the stomach exposed to increasing amounts of acid as a result of the splashing effect. There is also increased intra-abdominal pressure which results in gastric compression. This compression exposes the proximal stomach to acidic contents of the stomach as depicted below.

Additionally, blood flow is considerably altered during periods of intense exercise. During these periods, blood flow is directed to the muscles where more oxygen is required in energy production. This reduces oxygenated blood flow to the stomach increasing stomach pH. During period of intense exercise, horses have also been found to depict altered eating behaviors. This tends to affect the overall pH levels in the stomach.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Scientific research has shown that NSAIDs increases risks of developing ilcers in both humans as well as animals, particularly in high performance horses (Kellon, 2008). NSAIDs are associated with the formation of ulcers in the cecum and the colon. They inhibit the development production of prostaglandins which in turn interrupts mucosal blood flow and mucus.

The rate at which NSAIDs trigger the development of ulcers varies from one horse to another. There is a general variance in a horse’s tolerance to NSAIDs dependent on specific factors unique to a horse, including physiology. The most common NSAIDs prescribed for horses include phenylbutazone or banamine. Owing to the fact that the tolerance levels of horses cannot be predetermined, it general wisdom to use and administer these drugs in a conservative manner so as to realize the preferred therapeutic effect.

Stress

Gastric ulcers have been found to be most common in horses that are exposed to physical and behavioral stress. General stress levels experienced by a horse influences the likelihood of developing gastric ulcers.

Physical Stress

Constant, regular and prolonged high performance activities tend to a have a toll on the physical aspects of both humans and animals. High intensity activities result in instances of pains and aches that increase the chances of developing gastric ulcers in both humans and animals. As such, alleviation of physical pain is an essential aspect of gastric ulcer treatment.

Behavioral Stress

Stall Confinement

Recent epidemiological studies have found that horses are more susceptible to developing intestinal inflammation, colic and gastric ulcers when they are confined in stall for extended periods of time. Horses are physiologically designed and predisposed to constantly move around (Cole, Bentz, & Maxwell, 2014). This free and moderate type of exercise tends to enhance digestion efficiency, unlike intense exercises that impedes the digestion process. Furthermore, stall confinement is associated with bolus feeding, i.e. two large meals during the day. This increases risks of developing gastric ulcers. This lack of constant supply of nutrition reduces the constant flow of saliva, increasing the risks of developing gastric ulcers.

Transport

High performance horses are moved a number of times within a relatively short amount of time. This is largely owing to the varying schedule and geographic locations of high performance events. This constant moving induces behavioral stress on the horse as it deviates from its naturally predisposed habits of free range movement. Prolonged exposure to period of transportation leads to the gradual development of gastric ulcers due to the affected eating habits and general behavioral patterns.

Emotional Stress

High performance horses are sometimes exposed to a number of emotional stress dynamics during active racing and training. Like human beings, the emotional state of a horse considerably influences their health. Other horses will depict this stress externally evident in very physically reactive episodes while other will internalize these emotions, appearing stoic and benign (Crabbe, 2007). Horses that tend to internalize these emotions are even more prone to developing gastric ulcers as this is their body’s way of channeling the emotional stress. More hyper-active and reactive horses tend to be less prone to developing gastric ulcers as a result of emotional stress.

Dietary Factors

Cereal and High-Concentrate Diets

Horses that consume large amounts of gran such as corn, oats and barley usually experience an increase in volatile fatty acids production in the stomach. The increase in volatile fatty acids in the horse’s stomach usually leads to the decrease in stomach pH levels. This low pH creates the ample environment for the development of ulcers and inflammation of the gastric tissues.

Furthermore, there is a risk of grain fermentation by resident bacteria. This fermentation process leads to the production of acidic byproducts such as VFAs, alcohols and lactic acid. Abbot 18% to 20% of VFAs produce butyric acid. These would serve to lower the pH, creating ample environment for the development of gastric ulcers.

Intermittent Feeding

High performance horses are usually placed on intermittent feeding where they go instances deprived of nutrition for the sake of performance. As a result, they are more prone to developing gastric ulcers. A horse’s physiological is naturally designed and is predisposed to consistent grazing or feeding. This requires a consistent flow of food through their stomach in relatively short intervals throughout the day.  A horse can digest all food in its stomach within 4 hours, given it does not have access to nutrition during this time (Vandergrift, 2014). Despite the fact that the horse may be on an empty stomach, the production of acid does not cease. This exposes the stomach to direct contact with the acid on a daily basis, reducing stomach pH over time and increasing the chances of developing gastric ulcers.

A horse that experiencing intermittent feeding and considerable spells on an empty stomach build up hydrochloric acid within their stomachs. As depicted in the graphical representation above, when a horse is subjected to 24 hours of no nutritional intake, the gastric pH levels are seen to be below the most ideal stomach pH. This creates the ample environment for the development of ulcers. However, when a horse is subjected to 24 hours of free choice feeding, from grazing to hay, the horse depicts ideal pH levels.

A horse experiencing continuous feeding has a continuous flow of ingesta and saliva that are essential in buffering stomach acid. This helps maintain higher pH levels throughout the day and reducing the risk of developing gastric ulcers.

For this reason, horses at pastures depict low prevalence levels of gastric ulcers. This is predominantly due to the fact that free range grazing provides the animal with enough roughage required to reduce the effect of the constant production of gastric acid. Intermittent feeding has been found to have a considerable effect on gastric pH over a 24-hour period.

Symptoms of Gastric Ulcers

Most of the horses with a certain diagnosis of gastric ulcers are the off-track thorough breeds that have been retired from racing. A gastroscopy confirms a gastric ulcers diagnosis. However, such a diagnosis can be arrived at by careful observation and tracking of animal behavior as certain animal behavior is associated with gastric ulcers. For example, omeprazole can be introduced to on an individual and followed up with behavioral monitoring.

Some of the common behavioral symptoms include;

• Snarky attitude
• Resistant to being groomed
• Poor appetite
• Over-reaction to normal stimuli
• Non-compliance under saddle
• Bad breadth
• Colic symptoms during or just after consuming a grain meal
• Off-smell to manure
• Poor hair coat quality
• Loose manure
• Low body condition score(Reese & Andrews, 2009)

It is important to note that these clinical symptoms may indicate a number of other complication as they are not unique to gastric ulcers. They are not specific to gastric ulcers but are suggestive. However, when a number of these symptoms simultaneously occur in a horse, it is an important indicator of gastric ulcers

Treatment and Prevention

It is important to apply medical intervention in treating gastric ulcers. Special attention is required by highly skilled or experienced personnel. Nutritional management should be employed to supplement medical treatment and mitigate the recurrence of gastric ulcers. The first steps would entail strategies employed to eliminate the clinical signs of gastric ulcers.

Relieve Stress

The first and most important step to treating gastric ulcers is relieving the horse of all forms of stress. The most common triggers and accelerants of the development of gastric ulcers entail emotional and behavioral stress (Crabbe, 2007). As indicated earlier, retired off-track through bred are most susceptible to gastric ulcers. As such, these horses have been subjected to a considerable amount of prolonged behavioral and emotional stress in the course of their life as high-performance horses.

Stall confinement increases the risks of a horse developing gastric complications and ulcers. As such, a horse suffering from gastric ulcers would considerably befit from free range living spaces. It is essential that this transition from confinement to free-range be gradual and progressive. This is because a sudden shift in behavioral patterns in horse may not be suitable for optimal health conditions and status.

Dietary Factors

Achieving normal digestive function and weight is a vital goal in treating gastric ulcers. As such, good quality hay is essential for movement towards optimal digestive functions. Research shows that alfalfa hay provides the best results in treating gastric ulcers in horses. This type of hay has a considerable buffering effect on the stomach.

Mitigating Fasting

One of the main triggers for a reduction in stomach pH is extended periods of nutrition deprivation. To realize normal digestion, it is important that a horse receives constant supply of free choice feed, from free range grazing on grass to high quality hay

Roughage

As horses continually produce gastric acid, it is important that the stomach receives considerable buffering, enough to withstand the constant production of gastric acid. As such, roughage is an important factor in a horse’s diet. There are numerous techniques that increase the amount of roughage within a diet.

Pasture Turnout

Free range grazing has been identified to have considerable effects in reducing behavioral stress in animals. However, the dietary implications of free range grazing are crucial to the rapid healing of gastric ulcers and the recovery to optimal activity. Free range grazing allows the horse to potentially feed on a variety of grass that provides it with a considerable amount of roughage. Even though roughage from free range is important, it is not stuffiest. Free choice hay is important in supplementing the roughage content within the det. Free-choice hay provides the horse with all the necessary fiber required to ensure efficient and optimal digestion.

Alfalfa Hay

Nutraceutical ingredients such as glutamine and carnitine are essential supplement to alfalfa as they boost the healing process in intestinal and gastric cells. Furthermore, it enhances resistance against recurrence of ulcerations. Alfalfa hay has been found to have relatively instant effects on an animal’s behavior. Within the first 12 and 24 hours of feeding alfalfa hay, a horse realizes a rebound in hyperactivity as depicted in the graph below. (Kellon, 2008)

Other Dietary Factors

Horses require other dietary factors to help speed up the healing process in gastric and intestinal cells while enhancing resistance to future ulceration. These include;

• vegetable oils
• fish oils
• probiotics
• mineral buffers (magnesium and calcium)
• pectin
• lecithin(Durham, 2013)

One of the simplest ways to provide a horse with all the required supplements is introduction of Triple Cow Senior feed. This is a beet pulp-based feed that has little sugar and starch content with no grain. Beet pulp has been found to be very effective as it is very rich in pectin. Furthermore, Triple Crown Senior contains most of the required supplements such as lecithin, calcium, magnesium probiotics, prebiotic and 10% fat from vegetable oil. Sever case of gastric ulcers require more attention and additional supplements to help control the gastric ulcers. Fish oil and EquiVision’s ADR are important additions to such cases (Durham, 2013).

Recommendations

Roughage is an essential aspect of an efficient diet and it should be provided at all times. Employing the use of alfalfa hay is an affordable and readily available alternative to constant supply of roughage.

Concentrations should be moderately employed in the diet. Small amounts evenly distributed in a minimum of 3 feedings per day is sufficient for a horse’s dietary needs. These concentrates should not surpass 500 grams of grain per 100 kg of body weight.

Corn oil is an important dietary management tool. It is integral in decreasing stomach acid within a short amount of time. Prolonged used of corn oil increases the protective properties within the stomach. It also provides Omega 3 and Omega 6 fatty acids crucial for optimal digestion and pH control. Ideally, horses should receive 8 oz. at least once in 24 hours.

Rice bran or rice bran oil has protective factors essential for the stomach lining. However, its use has to be closely monitored as a result of rancidity which produce ketoaldehydes known to be ulcerogenic. This can be mitigated by steam pasteurization and refrigeration.

Stress management is an essential tool in mitigating occurrences and development of gastric ulcers. This can be achieved by limiting over cording, trailering, long-term stall confinements, semen collection and natural breeding.

Medical management of EGUS mainly employs neutralizing agents (such as antacids), anti-secretory agents (such as Histamine H2 receptor antagonists and Acid pump inhibitors) and other techniques such as antibiotics and Acid pump inhibitors.

Conclusions

Equine Gastric Ulcer Syndrome (EGUS) is a condition in horses, mostly found in race horses, characterized by the development of ulcers in the glandular (distal) stomach, squamous (proximal) stomach, proximal duodenum and terminal esophagus. Breeding stallions and pregnant mares are also naturally predisposed to develop EGUS. It affects the health, performance and maintenance costs of horses. Effective treatment techniques and methodologies entail the manipulating diet, environmental factors and medical interventions.

References

Cole, C., Bentz, B. G., & Maxwell, L. (2014). Equine pharmacology. Ames: Wiley-Blackwell.

Crabbe, B. (2007). The comprehensive guide to equine veterinary medicine. New York: Sterling.

Durham, A. (2013, November 18). Equine Gastrointestinal Dietary Management. Veterinary Times, 22-24. Retrieved March 19, 2015, from http://www.vetsonline.com/media/c2d/40707ab0fe3279e8fb8684ab16eb6.pdf

Geor, R. J., Harris, P., & Coenen, M. (2013). Equine Applied and Clinical Nutrition: Health, Welfare and Performance.Edinburgh: Saunders Elsevier. Retrieved March 19, 2015, from https://books.google.com/books?id=rlBfYgLiqtwC&pg=PA566&lpg=PA566&dq=Influence+of+diet+and+nutrition+on+equine+gastric+ulcers&source=bl&ots=SgeKSDQN1r&sig=swM2zjB0fTRYg_I_yf0e7sU3sPY&hl=en&sa=X&ei=SEIKVYDKBdDTgwTMhoSgBw&ved=0CE0Q6AEwBg#v=onepage&q=Influen

Huntington, P., & Myers, J. (2004). Horse sense : the guide to horse care in Australia and New Zealand (2nd ed.). Melbourne: Saunders Elsevier.

Kellon, E. (2008). Horse journal guide to equine supplements and nutraceuticals. Guliford: Lynn Press.

Reese, R. E., & Andrews, F. M. (2009, April). Nutrition and Dietary Management of Equine Gastric Ulcer Syndrome. Veterinary Clinics of North American Equine Practice, 25(1), 79-92. Retrieved March 19, 2015, from http://www.researchgate.net/profile/Frank_Andrews/publication/24217127_Nutrition_and_dietary_management_of_equine_gastric_ulcer_syndrome/links/0c960525fd9b1afc62000000.pdf?origin=publication_detail

Sprayberry, K. A., & Robinson, E. (2014). Robinson’s current therapy in equine medicine. St. Louis: Elsevier.

Vandergrift, B. (2014). Gastric Ulcers and the Off-Track Thoroughbred. [S.I]: Tripple Crown Nutrition, Inc. Retrieved March 19, 2015, from http://www.triplecrownfeed.com/wp-content/uploads/2014/04/GastricUlcersOff-TrackThoroughbred.pdf