Feed Management of Good Doer Horses with Gastric Ulcers

Article last updated: 1st November 2022

Over the last decade, studies have increased our awareness and understanding of Equine Gastric Ulcer Syndrome (EGUS). Although horses with ulcers were historically thought to typically be underweight and poor doers, this is no longer the case. A recent study from Belgium showed that only half of those with ulcers were underweight. So much guidance relating to ulcers centres on feeding plenty of forage but what if this means your horse puts on weight? How do we find the balance between feeding enough but not too much forage?

Symptoms of gastric ulcers in horses

Symptoms of gastric ulcers are not always very easy to distinguish from other issues or diseases but some common ones include weight loss, dull coat, biting when being girthed and intermittent colic. However, it is important to consider that good doers and horses that look healthy on the outside can have ulcers too. It is also apparent that there is no link between the severity of ulcers and the symptoms – some horses are clearly very stoic and can have grade 4 ulcers with no obvious clinical signs.

There are some practices that are known to increase the risk of horses having ulcers:

  • Feeding too little fibre – chewing fibre produces more than double the amount of saliva than chewing concentrates
  • Feeding 2g/kg BW starch per day or 1g/kg BW per meal more than doubled the risk of a horse having ulcers.

So if too little forage is a risk factor, how much forage should I feed my horse?

The levels recommended have changed over the years which is one reason some confusion exists. The increasing frequency with which ulcers is being diagnosed may account for why the recommendations for minimal dry matter intake tend to increase in more recent studies. The consensus amongst most vets and nutritionists for the long term management of good doers is 1.5% of current bodyweight on a dry matter basis. Let’s break this down a little bit more to understand why:

  • 1.5% – earlier studies have gone as low as 1% of bodyweight and whilst no adverse effects on welfare of the horse were found, the studies didn’t look for ulcers and lasted a maximum of a few months.
  • Current bodyweight – we advocate using the horse’s current bodyweight as it is less subjective than trying to estimate what the horse’s ideal bodyweight should be. If the weight loss program works, then the intake required will gradually reduce in line with the horse’s weight loss. A gradual reduction in intake is a much safer approach to maintaining digestive health than one big drop.
  • On a dry matter basis – wetter forages such as haylage may only contain 60% dry matter whereas hay is around 85% dry matter. If recommendation are given on an as fed basis, a horse receiving haylage will be consuming much less fibre than the horse on hay as 40% of what is consumed is water. If trying to calculate how much forage your horse can have on a dry matter basis is confusing please don’t be embarrassed to ask for help – our nutritionists will do this for you so you know you are using the right amount, simply click here to fill in our Feed Advice Form
  • Long term management – to deal with an acute significant obesity or laminitis situation it may be necessary to reduce to below 1.5% for 3-6 months for example. The aim would always be to return to at least 1.5% as soon as possible to reduce the risk of other health issues such as ulcers.

Can straw be fed to horses with ulcers?

Back in 2009, a study that looked at the incidence of gastric ulceration in a population of horses found that those that were fed straw as the sole or predominant fibre source were more likely to have ulcers. The reasons given related to the structure of straw and the fact that straw contains low levels of calcium and protein. This makes sense given that it is alfalfa’s naturally high protein and calcium levels that are thought to make it a superior buffer.

However, the key here is that straw was used as the sole or predominant fibre source which is not typically done in the UK. Recognising that straw can be useful as a low-calorie forage source for good doers, a follow up study has been published investigating the safety of feeding 50% wheat straw to replace haylage. The study by Jansson et al (2021) found no ill effects and specifically looked for gastric ulcers. Some simple calculations show that if straw replaces 1/3 of the weight of an average hay, a reduction in energy intake of 16% is achieved. Obviously replacing half the haylage ration will achieve an even greater reduction.

Click here for further information on feeding straw to horses.

Should my ulcer prone horse have a bucket feed?

Whilst the significant majority of any horse’s diet should be forage, even good do-ers can benefit from a bucket feed to provide a balanced diet. UK pastures lack a number of key trace minerals including zinc, copper and selenium and these nutrients are important for many different functions such as energy breakdown and utilisation and as part of the body’s antioxidant defence system. Topping up these nutrients by adding a broad-spectrum vitamin and mineral supplement or balancer to a low calorie chopped fibre feed to act as a carrier helps to ensure a balanced diet is supplied. Feeding a double handful of a chopped fibre feed in the 20-25 minutes before exercising is also recommended to help prevent ‘acid splash’ in the non-glandular region of the horse’s stomach. The fibre ensures the stomach isn’t empty and suppresses the movement of the acidic contents when the horse moves.

For poorer doers and those in harder levels of work, forage may not be sufficient to keep them in an acceptable condition and so the bucket feed is an important part of the ration. There are a range of feeds with the BETA approval mark for horses and ponies prone to EGUS which range in ingredients and type. Many contain alfalfa to a lesser or greater extent but its suitability for those prone to ulcers has caused some confusion.

Can I use alfalfa for horses with ulcers?

The simple answer is yes you can. Studies back in the early 2000s (Nadeua et al, 2000; Lybbert et al, 2007) showed that alfalfa was more beneficial for horses with ulcers (ESGD) compared to grass forages, as the high levels of calcium and magnesium it contains act as natural buffers to acidity.

Why does alfalfa contain more calcium than grass forages?

Alfalfa has really deep roots – about 3 to 4 metres – and the calcium at this depth in the soil is more available for absorption. This means that alfalfa plants can take up more calcium than grass – chopped alfalfa contains between 30 and 50% more calcium than grass forages. Early studies suggest that omeprazole is reducing calcium absorption in the horse as is seen in humans and in Swanhall et al’s (2018) study, they recommend using bio-available calcium sources in the diet to help counteract this effect. Plant based sources of calcium such as alfalfa are much easier for the horse to absorb than inorganic sources such as limestone flour.

Top Tips for Feeding the Good Doer Horse with Gastric Ulcers

  • Make fibre the foundation of the diet, both long stem and short chop, topping up with a supplement or balancer to provide a balanced ration
  • Keep fibre intake as maximal as possible whilst managing bodyweight by using late cut hay and other lower calorie fibre sources such as Hi-Fi Molasses Free, Healthy Hooves Molasses Free or Ulser Lite
  • Feed regular forage feeds split into as many small meals as possible when your horse is not at grass leaving a larger quantity overnight
  • Feed a small alfalfa based meal prior to exercising
  • Make sure your horse has constant access to water
Dugdale et al (2010) Effect of dietary restriction on body condition, composition and welfare of overweight and obese pony mares. Equine Veterinary Journal, 42 (7) 600-610.
Jansson et al (2021) Straw as an Alternative to Grass Forage in Horses—Effects on Post-Prandial Metabolic Profile, Energy Intake, Behaviour and Gastric Ulceration. Animals. 11.
Lybbert, T. et al (2007), Proceedings of Annual Convention of the AAEP, Orlando, Florida, 2007.
Morgan et al (2016) Treatment of Equine Metabolic Syndrome: A clinical case series. Equine Veterinary Journal. 48. 422-426.
Nadeau, J. et al (2000) Evaluation of diet as a cause of gastric ulcers in horses. American Journal of Veterinary Research. Jul;61(7):784-90.
Rendle et al (2020) Tackling obesity and related laminitis in equine patients. Veterinary Times Equine, 6 (1) 6-9.
Swanhall et al (2018) Mineral and Vitamin Supplementation Including Marine Derived Calcium Increases Bone Density in Thoroughbreds. Proceedings of the Australasian Equine Science Symposium