Hindgut Ulcers – Your Ultimate Guide
Preventing and managing hindgut ulcers is becoming an all-too-common scenario. What was once thought to be fiction has rapidly become more of a fact. Particularly as research into this area of digestion has evolved. With a positive diagnosis, it’s easy to feel as if your world has come crashing down. However, with the help of this ultimate guide, find out how to manage this problem and get your horse back to feeling healthy and happy.
When we talk about the horse’s hindgut, we’re referring to the digestive area from the cecum to the rectum. The primary function of the hindgut is to digest fibre and convert it into useable energy from volatile fatty acids. High levels of this fermentative microbial digestion take place in the caecum by microorganisms, yeast, and friendly bacteria.
The normal acidity (PH) level in the hindgut is around 6.2. When the acidity in the hindgut is raised it lowers the pH. Lactate-producing and lactate-utilizing bacteria (bugs that cause issues) get strong in an environment with a low pH. They then start producing lactic acid rather than volatile fatty acids. This change in the microbial populations and acid proﬁles is what creates hindgut acidosis.
What causes this change to occur?
It’s caused by large quantities of undigested simple carbohydrates reaching the hindgut and producing lactic acid. These are usually starches and sugars found in processed grain feeds or rich pasture. This drop-in pH may reduce mucous production, leaving the mucous membranes of the hindgut vulnerable.
Furthermore, when fiber-digesting bacteria die off because of hindgut acidosis, endotoxins are released into the bloodstream. The result of this can cause issues such as laminitis.
What are Hindgut Ulcers?
- Hindgut ulcers are also known as colonic ulcers and are often referred to by vets as Right Dorsal Colitis (RDC). This is because most hindgut ulcers occur in this part of the large intestine on the right side of the horse.
- All ages and breeds of horses are susceptible. Hindgut ulcers have been reported to affect 44 – 63% of horses and are estimated to occur in 65% of sport horses. These types of ulcers can go undiagnosed for months because horses are usually normal between acute episodes.
- When hindgut health is compromised, a horse may also have trouble absorbing important nutrients. This can result in poor coat and hoof condition, reduced immune function, and behavioural changes.
- Whilst hindgut ulcers are less common than gastric ulcers, a horse can have both at the same time.
A definitive diagnosis is difficult because a gastroscope (used to diagnose gastric ulcers) won’t reach the colon.
However, one definitive method of diagnosis is a Transabdominal ultrasound. This type of ultrasound takes specialized equipment and skill on the part of the vet. If the ultrasound shows a thickened colonic wall, hindgut ulcers are likely to be diagnosed. If you’re concerned about hindgut acidity, ask your vet to test faecal pH first.
Horses affected by hindgut ulcers may experience a progression of signs such as
- decreased performance, lethargy
- weight/topline loss
- reduced appetite
- diarrhea, intermittent soft manure, or “squirty” bum where some horses have a liquid component that follows passing otherwise normal manure
- mild intermittent or recurring colic
- a rough coat
- a change in attitude, sudden girthiness
- sensitivity in the flank area
- difficulty bending, collecting and extending
- blood in the manure
- chewing wood (cribbing)
- swelling (oedema) along the central midline of the belly
Why do Horses get Hindgut Ulcers?
- Stress for horses can be either physical (i.e. training and performance) and/or emotional stress (i.e. separation anxiety, floating). This leaves them at a higher risk for developing both gastric and hindgut ulcers. Additionally, stress, whether physical or mental, affects the horseʼs immune system.
- Hindgut acidosis. Usually, but not always, caused by starch overload or massive doses of pure fructan and insufficient forage. Horses with hindgut acidosis often have frequent low-grade colic, loose manure, and are off their feed.
- Overuse of non-steroidal anti-inflammatory drugs (NSAIDs). These should be used for no longer than 5-7 consecutive days. Overuse can lead to damage to mucosal membranes of the gut lining and interfere with blood clotting.
- Parasites including tapeworm, small strongyles, and others. These may also cause ulcers at the site where they attach to the intestinal wall.
- Disturbances to the gut microbiome. Eg excess levels of lactic acid are caused by a decrease in the pH level of the colon. This acidic environment may result in:
- Damage to the mucosal lining, resulting in compromised intestinal barrier function.
- Changes in the equine microbiome eg a proliferation of pathogenic bacteria and a decrease in the population of beneficial bacteria.
- Reduced defences against toxins in the gastrointestinal tract.
BE AWARE OF OTHER CONDITIONS that could look like RDC. These include
- Gastric ulcers
- Other causes of colic (large colon displacement and/or impaction)
- Infectious causes of diarrhea (Salmonellosis, Clostridium)
- Inflammatory bowel disease
Three Steps in the Prevention and Treatment of Hindgut Ulcers
Dietary management that prevents hindgut ulcers from recurring and to support the healing of the intestinal lining.
- Your vet may prescribe medications such as sucralfate or misoprostol.
- Reduce the amount of work the colon must do by limiting long fibre (hay) consumption. Replace it with short fibre eg hay cubes, pellets, or chopped hay.
- Offer small, frequent meals whenever possible to support gut health and improve nutrient absorption.
- Try feeding Psyllium. It can help lubricate and shorten the transit time for feed and roughage. It also increases water content in the intestines and fatty acid concentration in the colon and reduces inflammation.
- Feed to provide buffering to the hindgut i.e. beet pulp, soyhull husks
Minimizing stress is an important part of recovery from Right Dorsal Colitis. This can be done by:
- Reducing strenuous exercise or training
- Providing more turnout time
- Minimalising transport
By following as many of the above strategies, you can usually see a reduction in symptoms after 1-2 weeks. However, be aware that it can take two to three months for ulcers to fully heal.
Improve digestive health. Probiotics and prebiotics can be helpful.
Can Fibregenix Platinum Pro performance balancer help with hindgut ulcers?
Yes! Platinum Pro is invaluable in the management of hindgut ulcers. It includes 4 specific digestive aids. Actisaf Live yeast probiotic, purified nucleotides, MOS, and FOS prebiotics will tackle each of the points listed below. Each of these digestive aids has proven performance when it comes to gut health.
- For increasing the number of “good” bacteria and restoring gut health in horses with hindgut ulcers.
- To improve feed efficiency and support nutrient assimilation
- Supporting hindgut function and fibre fermentation
- Assisting in the combat of toxins by inhibiting their absorption from the gut
- Supporting the immune system by increasing immunoglobulin activity
Dietary Nucleotides are of particular interest. Here are 2 reasons why we’ve included them in our balancers for preventing and managing hindgut ulcers.
Dietary Nucleotides Improve Efficiency of Cell Growth and Repair
In general, DNA is synthesized through complicated de novo pathways. These pathways create fresh nucleotides from scratch rather than using existing material. However, in the presence of dietary nucleotides, the body can down-regulate DNA synthesis. And instead, it uses an enzyme named HGPRT to scavenge the intact nucleotides improving the efficiency of cell repair and conserving energy.
In addition to ongoing maintenance, cell division is critical for repairing damaged tissue, including ulcers. This is why in times of stress, dietary nucleotides have proven to be beneficial.
Dietary Nucleotides Increase Mucosal Thickness
Nucleotides optimize the natural protective mechanisms of the mucosal lining. This helps to maintain a healthy GI tract. Supplementing a horse’s diet with nucleotides increases mucosal thickness and protein levels through increased availability of genetic precursors. It also speeds up intestinal recovery after chronic diarrhea and intestinal damage.
Nucleotides play a critical role in the body in that they accelerate the cell regeneration process. Cell regeneration allows an animal to recover much quicker from the type of stress it is under (performance, illness, disease, injury, etc.).
TAKE HOME MESSAGE
Hindgut acidosis is a nutritional problem. You feed your horse – that makes it your problem!
Consider where your horse came from that would affect his digestion. Off-track racehorses, rescued horses, performance horses, or simply grain fed at any time in his/her life. All these will have a higher risk. In fact, any horse is at risk of hindgut acidosis from conditions that don’t support microbial digestion.
The signs of hindgut ulcers should always be taken seriously. If you suspect your horse might be affected by hindgut ulcers, get him examined by your vet as soon as possible.
In some cases, hindgut ulcers might be unavoidable. However, you can greatly reduce his chances of developing this debilitating condition. The bottom line is to limit NSAID use, minimize stress whenever possible and manage/feed your horse appropriately.
Feeding Oils and Fats to Horses – The Natural supplies of Omega 3 and 6
Feeding oils and fats to horses is commonplace in today’s modern nutritional practices. As a herbivore, horses are adapted to a diet naturally higher proportionally in Omega 3 fatty acids (ALA) compared to Omega 6 (LA).
This natural supply of Omega 3 and 6 comes from fresh grass. Although low in total fat (2-4%) a significant proportion of that fat (39-56%) is alpha-linoleic acid (ALA) compared to Linoleic Acid (LA.) The ratio is approx 4:1 ratio of ALA to LA. Once grass is cut and dried to produce hay however, the naturally occurring unsaturated fatty acids are destroyed by oxygen. So, if hay is the main forage source for your horse, you need to add a fat source offering more omega 3 than omega 6.
Omega 3 and 6 are regarded as Essential Fatty Acids, meaning the horse cannot manufacture them for itself. Supplementing with oils or fats that contain higher levels of Omega 3 than Omega 6 has proven to be beneficial to all horses. Especially those that aren’t eating fresh grass pasture for at least 18 hours per day.
Feeding Oils and Fats to horses – What’s the difference?
Oils and fats are essentially the same. It’s just that oils describe fats that are liquid at room temperature, whilst fats are solid at room temperature. There’s plenty of choice when it comes to feeding oils and fats to horses. And they can come in a number of different forms such as oils, seeds, pellets or ground ‘meals’.They’re considered slow release energy sources which mean they gradually release energy into the horse’s blood stream. This helps to reduce the risk of hyperactive behaviour. Feeding oils and fats to horses alongside a good quality fibre can also be of considerable benefit for improving condition. This is because they have twice as many calories as carbohydrates making them very calorie dense. For example, did you know that one cup of oil provides the same amount of digestible energy as approx 0.55kg of oats?
Depending on the source, oil has Digestible Energy levels of 20-38 MJ/kg. This compares to a typical value of 8MJ/kg for hay, 12-14MJkg for super fibres and 9-11MJ/kg for cereals.
Triglycerides and omega 3, 6, and 9
Oils such as linseed, sunflower, corn and soya contain a lot of different fatty, acid-rich substances called triglycerides. Triglycerides themselves are made up of different types of fatty acids, including the omega-6 or omega-3s. They’re often referred to as poly-unsaturated fatty acids (PUFAs).
When it comes to deciding which oil you should be feeding your horse, it’s important to remember that all oils have the same amount of energy and it’s their ratio of Omega 3 and 6 which separates them. Omega 3, is known as alpha linolenic acid (ALA) and Omega 6 is known as linoleic acid (LA)
Omega 3 and 6 EFAs play a very important role within the equine diet. They work synergistically within the horse’s body and balancing these essential atty acids is paramount to optimal digestive health. Research has shown that the appropriate ratio would be in the region of 2-5:1 Om 3:6.
Deficiencies of Omega 3 can, for example, affect your horse’s temperament, and deficiencies in Omega 3 can even lead to hoof problems and allergic skin conditions.
Two very important omega-3 fatty acids
These are eicosapentaenoic acid, (EPA) and docosahexaenoic (DHA). They’re the building blocks for hormones and also have an important role in the following:
- The structure and formation of the wall of red blood cells. This is essential for competition and performance horses where oxygen transportation can be improved by the structure of the red blood cells.
- Essential component of soft tissue structure
- Hormone activity
- Central biochemical role
- Energy storage system
- Providing energy that by passes the anaerobic stages that are associated with muscle fatigue and “fast release” energy
- Being an excellent source of concentrated energy
- Physical insulation and protection of body organs
- Maintaining conformity and combatting excessive heat loss
- immune function and tissue repair within the horse’s body
Most oils contain Omega 9. This is a non-essential fatty acid and very little is known about the horse’s requirements. It can be synthesized by the horse from unsaturated fats. However, if Omega 3 and 6 intake is low then of course Omega 9 must come from the diet.
Feeding Oils and Fats to Horses – The best sources of Omega 3 and 6 and Their Benefits
Linseed oil is almost 60% pure Omega-3 fatty acids and is one of the richest plant based sources of Omega-3. Omega-3 is a natural anti-inflammatory helping to reduce prostaglandins responsible for pain and inflammation in the horse’s body.
- Omega-3 is a natural anti-inflammatory helping to reduce prostaglandins responsible for pain and inflammation in the horse’s body.
- Omega 3 oils have been shown to have an important role in the structure and formation of the wall of red blood cells, which is essential for competition and performance horses where oxygen transportation can be improved by the structure of the red blood cells.
Deficiencies in Omega 3 can lead to
- hoof problems
- allergic skin conditions.
- temperament issues
Conversely, Omega 6 is equally important to the equine diet and is most commonly found in corn, canola, rice bran, primrose, and sunflower oils. Soya oil is also a rich source of Omega-6 at almost 50% Omega-6.
Omega 6 is a natural pro-inflammatory and is essential for immune function and tissue repair within the horse’s body.
Too much Omega 6 can have adverse implications on your horse’s health for example:
- inflammation in joints and muscles. The aging joints of older horses are more painful when omega 6 fatty acid is fed in large amounts.
- tissue damage from oxidative stress caused by inflammation.
The table left, shows some of the commonly fed oils and their proportion of Omega 3 and 6.
How much should I Feed?
This will depend on your feeding goals. It may take only half a cup of oil a day to add shine to a horse’s coat. However, if you’re adding oil for performance benefits then 1-2 cups of oils for a 500kg horse may be needed. Any supplemental oil should always be added gradually to the horse’s feed to avoid digestive problems. Remember also that when feeding oil, additional vitamin E at a rate of 1IU of vitamin E per 1ml of oil may be required to help prevent peroxidative damage. Some oils may already include this, likewise fat pellets may already have vitamin E included for this purpose.
As with any other nutritional rule, moderation is the key. A daily intake of 2-5% of feed as oil is sufficient for most situations. It can be increased slightly for the onset of winter, or where a moderate to heavy level of activity is anticipated.
Supplementing your Horse with Oils and Fats – Can I feed too much?
Yes. As with any nutrient it’s possible to feed too much. When feeding fats and oils to horses, there are some important considerations to make:
- Be attentive to nutrient imbalances when top-dressing oil onto an existing ration. Eg high levels of fat in the diet may mean a higher need for antioxidants such as vitamin E
- Remember that higher rates of fat inclusion may increase the risk of digestive disturbances.
- Higher rates of fates may reduce calcium absorption via formation of mineral-fat soaps.
- Palatability may also be another factor to consider with some horses disliking oils but accepting it in a ‘meal’ form.
- Be mindful that ponies, donkeys, mules and minis are unable to tolerate high levels of fats.
- Fats shouldn’t be fed to horses that are already overweight/obese, or those prone to hyperlipemia.
- Avoid fats as part of an initial re-feeding programme for starved or severely malnourished horses. Many of these horses will have compromised gastrointestinal and organ function and will have a poor tolerance to digest them.
What’s a good alternative to oil?
Cereals and Fibres
You could fulfill the majority of energy requirements using a combination of cereal and fibre, especially super fibres. But not all horses need or can tolerate cereal feeds. Having said that, it’s actually impossible to feed a diet without fat, as it’s found in most feed stuffs albeit often as a seed meal. In this case small supplements of oil are all that are needed.
A High Quality Feed Balancer Supplement
Feeding a balancer with the correct, balanced level of Omega 3 and 6 fatty acids such as one from the Fibregenix range is a great way to ensure your horse or pony is getting everything he needs on a daily basis to ensure a nutritionally balanced diet. It can take approximately 30 – 90 days until the benefits of feeding these essential fatty acids can be seen. But once your horse has a balanced diet with the correct levels of Omega 3 to 6 oils, it will have an improved immune system, indicated by a glossy coat and his overall health and well-being.
Copra – A viable Alternative?
Coconut oil or more often coconut meal (copra) is commonly added to horses’ diets to promote condition. It is low in Omega 6 and crucially contains zero omega 3s. Therefore, if you feed this as your only source of fat and your horse has no access to grazing, your horse will become deficient in Omega 3. Coconut oil and copra are more than 90% saturated fatty acids consisting of over 60% medium chain triglycerides which don’t exist in grasses. One therefore has to query the value of feeding a saturated fat which a horse doesn’t usually get in his diet…
Whilst rich in the long chain Omega 3 fatty acids, EPA and DHA, fish oils are higher in LA than ALA and can be contaminated with heavy metals such as copper or mercury and organic pollutants such as PCBs or dioxins. This poses the question as to whether it’s worth the potential risk. Palatability can also be an issue for some horses. After all, a horse doesn’t normally eat fish!
Horses are very well adapted to utilising oils and fats in their diet, particularly as a source of energy. Always try and follow a horse’s natural vegetable diet and choose your oil/fat accordingly.
Reviewed and amended April 2021