Sucralfate is an FDA-approved drug for use in humans that is used off-label for the treatment of equine gastric and hindgut ulcers. It is typically used in conjunction with omeprazole.
Sucralfate (Carafate® Sulcrate®) helps to protect the lining of the stomach and colon, reducing pain and allowing ulcers to heal without sustaining further damage.
It works by reacting with hydrochloric acid in the stomach and forming a thick, viscous layer over any ulcerative craters. This keeps ulcers safe from gastric juices that can erode the stomach lining.
Sucralfate also modifies the environment of the stomach and small intestine to prevent the development of future ulcers. Consult with a veterinarian to determine whether sucralfate is appropriate for your horse.
Sucralfate to Treat Ulcers
Sucralfate is a hydroxy aluminum salt of sucrose octasulfate that works by binding to the mucosal lining of the stomach and colon.
It coats ulcerated tissue like a bandage, protecting ulcerative craters from further damage from stomach acid and digestive enzymes. Sucralfate also relieves pain and allows the stomach lining to heal. 
It is considered more effective for ulcers in the glandular region of the stomach but is used with other medicines for squamous, hindgut, duodenal, esophageal, and oral ulcers. 
This medication is available in oral tabs or a liquid formulation. The effects of this drug last for 6-8 hours and it must be re-administered 3-4 times per day to maintain efficacy.
Sucralfate vs. Omeprazole
When most owners hear their horse has ulcers, they immediately think of the proton pump inhibitor (PPI) Omeprazole as the prescribed treatment. However, increasing numbers of veterinarians are prescribing Sucralfate as an additional treatment for ulcers.
Omeprazole is effective for gastric ulcers and acts by reducing the production of stomach acid. It binds with the acid-producing cells of the stomach – called parietal cells – and interferes with their function.
Specifically, omeprazole inhibits the activity of the gastric enzyme ATPase. This prevents proton pumps in the parietal cells of the epithelial lining from functioning, which stops these cells from producing hydrochloric acid. 
By decreasing the acidity of the stomach, omeprazole gives ulcers an opportunity to heal and reduces the likelihood of new ulcers forming.
Sucralfate is beneficial to use with Omeprazole because it has a different mechanism of action, helping to reduce pain and protecting the stomach lining.
How Sucralfate Works
When given orally, Sucralfate forms a thick, sticky gel that is negatively charged and can bind positively charged proteins that are abundant in damaged tissue such as lesions in the stomach lining.
This gel protects the damaged area from further harm by forming a protective barrier that lasts 6-8 hours. At higher levels of gastric pH, Sucralfate has also been shown to: 
- Inactivate pepsin
- Absorb bile acids
- Buffer hydrogen ions
- Stimulate Prostaglandin E
- Increase bicarbonate secretion
- Slow gastric emptying and GI transit time
- Stimulate mucous secretion
These additional mechanisms of action may help to modify the gastric environment to support the body’s natural defenses against ulceration.
Pepsin is a gastric enzyme that the body releases to break down proteins found in food into their building blocks – peptides. These peptides can then be absorbed and used in the body.
Gastric chief cells that line the stomach secrete an inactive form of pepsin, called pepsinogen. This inactive form is known as a proenzyme.
In order for the proenzyme pepsinogen to be converted to its active enzyme form, the stomach environment must have a low pH of 1.5 – 2. The lower the pH, the more acidic the environment.
The horse’s stomach has a low pH as a result of parietal cells secreting hydrochloric acid. The production of stomach acid allows pepsin to be activated, so it can break down protein into peptides. 
Although pepsin plays a crucial role in the digestion and absorption of protein, it can also increase the severity of equine gastric ulcers. When pepsin and hydrochloric acid are present in the stomach along with already compromised mucosal tissue, pepsin can break down proteins found in the cell membrane. 
If cell membrane proteins are broken down, the cells die. This can result in deeper ulcer craters and increased pain for the horse.
Buffer Hydrogen Ions
Because Sucralfate is slightly basic, it can buffer or neutralize hydrogen ions and reduce acidity in the stomach.
The presence of hydrogen ions dictates the level of acidity in a solution. 
- More hydrogen ions = more acidity = lower pH
- Less hydrogen ions = less acidity = higher pH
Sucralfate buffers hydrogen ions in the stomach, reducing the acidity of gastric juices and reducing damage to the stomach lining. 
By buffering hydrogen ions and reducing acidity in the stomach, Sucralfate may help promote the healing of ulcers already present and could reduce the risk of new ulcers forming.
Stimulate Prostaglandin E
Prostaglandins are a group of lipids derived from arachidonic acid that are produced at the site of tissue damage. These natural chemicals help to promote healing and resolve inflammation.
Prostaglandin E acts in mucosal tissue found in the stomach lining to help combat ulcers by:
- Reducing inflammation
- Stimulating cellular repair
- Increasing mucosal blood flow
- Stimulating mucous production
- Increasing bicarbonate secretion (to buffer acids)
In humans and animal models, Sucralfate increases Prostaglandin E in both the stomach and the colon. When levels of prostaglandins are increased at the injury site, the ulcerated tissue can heal quicker and pain is reduced. 
Increase Bicarbonate Secretion
When your horse consumes food, it enters its stomach where it is churned and mixed with digestive enzymes and hydrochloric acid to break it down into easily absorbed molecules. This slurry then travels from the stomach to the small intestine.
In order to protect the tissues of the small intestine, the body secretes a buffer (or antacid) that reduces the acidity of the stomach contents.  If the acidity remained high, the intestinal walls would ulcerate.
Bicarbonate is a powerful buffer secreted by your horse’s pancreas to reduce the acidity of contents entering the small intestine. 
In animal models, studies indicate that Sucralfate can increase the amount of bicarbonate secreted by the pancreas.  This could help protect the horse’s small intestine and support nutrient absorption.
Slow Gastric Emptying and GI Transit Time
Sucralfate contains aluminum ions that are readily absorbed by your horse’s digestive tract. When these ions are absorbed, they bind to the smooth muscle cells that are responsible for pushing food through the digestive tract. 
Aluminum ions inhibit the action of smooth muscle cells, slowing the rate at which partially digested food moves out of the stomach.
This partially digested food and mucous coat the stomach, temporarily protecting the stomach lining from hydrochloric acid. If the partially digested slurry moves too quickly its protective effects are limited in duration.
Stimulate Mucous Secretion
Mucous is the stomach’s first line of defence against the damaging effects of hydrochloric acid. When the stomach doesn’t have adequate mucous protection, the sensitive tissues are vulnerable to acidic damage and ulcer formation. 
Mucous is secreted by goblet cells in the stomach and intestinal lining. Sucralfate stimulates goblet cells to increase mucous production, improving protection against ulcers. 
Support mucosal blood flow
Blood flow to the stomach lining is critical for supporting cells and the integrity of the tissue. It provides oxygen and nutrients that provide energy to the cells and serve as precursors for other molecules.
Sucralfate has been shown to increase mucosal blood flow in rats and helped protect the vasculature in the area from damage.  This can help tissue repair processes that are required to rebuild tissue that is damaged when gastric ulcers are present. 
Sucralfate Research in Horses
Sucralfate and Omeprazole
Sucralfate and omeprazole help resolve gastric ulcers through different mechanisms. When compared to each other, omeprazole is more effective than sucralfate alone at reducing the severity of glandular and squamous gastric ulcers. 
Sucralfate is commonly used in combination with Omeprazole. In one study, a group of 204 sport and leisure horses in the UK were given 12 mg/kg sucralfate twice daily along with 4 mg/kg omeprazole once daily. This combination resulted in a healing rate of 63.2%. 
In comparison, another study showed a healing rate of 22% following 28 days of 4 mg/kg omeprazole along with 10 mg/kg twice daily. 
Although there are differences in total healing in these two studies, more studies are required to determine the most effective protocol and for which horses sucralfate would be most beneficial. 
Sucralfate for Foals
Sucralfate can be administered to foals to address gastrointestinal issues including ulcers or to reduce the side effects of phenylbutazone treatment on GI health. However, there is limited research in this area and conflicting results.
In one study, sucralfate (4 grams per day) decreased phenylbutazone-induced gastric ulceration and hindgut pathologies in 3- to 4-month-old Belgian cross foals. 
In 6- to 7-month-old foals with naturally occurring subclinical gastric ulcers and inflammation, sucralfate (22 mg/kg every 8 hours) was no better at healing gastric lesions than corn syrup.  However, this study provided the treatment for just 15 days. Longer treatment duration may have shown greater differences.
Dosage and Administration Guidelines
Most veterinarians will instruct horse owners to give Sucralfate when their horse’s stomach is empty – commonly in the morning before grain or hay is given.
Sucralfate is only effective for 6-8 hours and must be administered several times per day. Because your horse’s stomach is likely to have food contents during the day, the first dosage is thought to be the most effective.
For gastric ulcers, veterinarians recommend giving Sucralfate at 10 – 20 mg/kg orally every 6-8 hours. For hindgut ulcers, Sucralfate is given at 22 mg/kg orally over the same period.
Liquid forms of this medication are considered more effective than tablets. If using tablets, it is recommended to crush the tablets to increase their protective effect. The tablets dissolve in lukewarm water, making them easier to administer. 
Sucralfate should not be given at the same time as Cimetidine or Ranitidine. These H2 blockers inhibit the production of hydrochloric acid in the stomach. Because Sucralfate forms a protective coating when it comes in contact with acid in the stomach, it should be given half an hour prior to Cimetidine or Ranitidine.
This medication is commonly used for a period of 21-28 days, but it can be used long-term in horses with high ulcer risk. Some horses are switched to a half dose for maintenance after the initial treatment period.
Store this medication in a sealed, light-resistant container away from children and pets.
Side Effects and Precautions
Sucralfate is not absorbed systemically and it has a low risk of adverse effects. Although rare, Sucralfate administration can cause some mild side effects including:
Sucralfate can slow gastric emptying and the transit time of food through the gastrointestinal tract. Because of this, some horses may experience mild colic symptoms associated with constipation. 
If your horse exhibits colic symptoms while on Sucralfate, call your veterinarian to discuss other treatment options.
Hypophosphatemia refers to a below-normal concentration of phosphorus in your horse’s blood. This side-effect is extremely rare and not well researched studied. Although it hasn’t been confirmed, researchers believe that the aluminum in Sucralfate may bind to phosphorus, reducing its absorption into the blood. 
Sucralfate may inhibit the absorption of other drugs and supplements, such as fluoroquinolones and tetracyclines.  It is recommended to administer this medication one hour before or two hours after meals.
There is a concern that long-term use could cause an accumulation of aluminum levels in the body, potentially contributing to cognitive issues or brittle bones. 
Caution is recommended, but sucralfate can be used in pregnant or nursing horses under the guidance of a veterinarian. 
Monitor your horse closely to determine whether sucralfate is working. If your horse develops blood in stools, or if your horse is grinding its teeth, contact your veterinarian immediately to determine whether the ulcers are worsening. 
Talk to your vet if you think your horse may have ulcers. They may suggest Omeprazole and Sucralfate along with diet and management changes.
Your vet may also suggest feeding your horse Visceral+, a safe and natural nutritional supplement that is clinically tested in horses with ulcers and shown to support a healthy gastric environment.
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