Treating Hindgut Ulcers

Treating Hindgut Ulcers

This is a common question we find all over the internet, and people giving advice on various forums. Someone somewhere once coined the term “hindgut ulcers”, and this has become the rage when speaking about gastric ulcers in horses. Many “knowledgeable” people with years of experience in owning horses will discuss at length their attempts at treating Hindgut Ulcers.

Treating Hindgut Ulcers


Hindgut Ulcers do not exist

Wait, what? What did I just say? Yes, there is no such thing as “hindgut ulcer syndrome” which correlates to the same meaning as “gastric ulcer syndrome” in horses. But what about all the supplements and products claiming they treat hindgut ulcers, and the various people claiming they know about treatment for hindgut ulcers in horses.

Okay, let me back up there a bit and clarify myself before you write an angry email to me claiming I don’t know what I’m talking about.

Hindgut ulcers do not exist in the way you think of normal gastric ulcers in the horses stomach. Instead of saying hindgut ulcers, we should rather be talking about a condition that could be referred to as colonic acidosis. The term “hindgut ulcers” was falsely attributed to an American university study which actually never took place. Instead, the “study” was actually an inspection of  horse carcasses in a slaughterhouse, undertaken by an owner of a supplement company that went on to produce a supplement for “hindgut ulcers” about 6 months later. Suspicious? I think so. These postmortem studies had no history of the horses involved, no access to medical history or living conditions prior to slaughter. Unfortunately, while it was a valuable study, it didn’t give the correct answers.

So now we know what Colonic Acidosis caused ulcers, we’ll just refer to them again as hindgut ulcers and make everyone comfortable with what they are reading.

What is Colonic Acidosis

So what is Colonic Acidosis, and what causes it? What actually causes the “hindgut ulcers” that everyone is referring to? Colonic Acidosis, also sometimes referred to as Hindgut Acidosis, is a condition that generally refers to the lowering of pH (an increase in acidity) in the cecum and/or colon of the horse. This happens when undigested starches and sugars reach the hindgut, instead of being absorbed by the small intestine.

Clinical Signs of hindgut ulcers

Hindgut ulcers tend to have more profound clinical signs than gastric ulcers, according to Andrews. Signs include a recurring lack of appetite, lethargy, intermittent fever, colic bouts, occasional edema on the belly from a loss of protein in the blood, weight loss and thin body condition. Typical signs can include a combination of loose manure and large fecal balls or, in some cases, complete diarrhoea. Liquid manure down the horse’s inner thighs and legs also serves as an indication.

What causes Colonic Acidosis Ulcers?

There are a few common conditions that cause ulceration in the horse’s hindgut. Ulceration in this case refers to an open sore or erosion in the lining of the intestine. Some of the most common are listed below:

  • tapeworm (or bots in the stomach) attachment sites.
  • migration and emergence of small or large Strongyle larvae
  • Intrusion of the lining by NSAID’s, such as Bute.
  • Less common – Overload of grain
  • Less common – huge doses of pure fructan (Read more about Fructans and horses)

How do you test your horse’s pH level?

There is a very simple, inexpensive way to test your horse’s pH level. You can get a food probe pH meter and test your horse’s fresh manure to detect the pH level. As a general rule, pH has to get below 6 to cause damage to the intestinal lining as detected by increased bacterial products circulating in the blood. You can then experiment with different feeding regimes to determine what brings your horse’s pH level up to a more acceptable level. No need to buy any fecal blood tests.

Obviously, you should discuss with your veterinarian at all times what you plan to do, and see what is causing the ulceration in the hindgut in the first place.

Further Reading:

  1. Signs of Subclinical Acidosis
  2. Clinically proven supplements in the USA for hindgut ulcers
  3. Dr Kellon: Hind Gut Ulcers
  4. Feeding horses with ulcers

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