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Gastric Ulcers

Foregut ulcers, alleged hindgut ulcers (a myth), and ... the (seriously not good) PPI effect

When we refer to ulcers, we're talking foregut ulcers. If you've been told your horse has hindgut 'ulcers', this is a myth - they don't exist because there are no acid-secreting cells in the hindgut. There is, however, hindgut acidosis, caused by lactic-acid being produced in the hindgut by lactic-acid bacteria. See our separate Hindgut Acidosis chapter.

How do ulcers happen? No rocket science involved

10-years or so ago, a study on gastric ulcers in horses was published which caused quite a stir in the scientific community.

Up to that point, scientists were more or less sure that ulcers were mainly a Thoroughbred problem; most racehorses had ulcers and the general thinking was that it was genetic, which generally tends to be the go-to reason when there's a health issue that equine medical pros don't understand.

Well guess what - it's not genetic. And this study was the first time that horses other than TBs were looked at, horses with no history of colic or other digestive issues, and - you've guessed it - a huge percentage, up to 80-90% of non-TBs, had gastric ulcers. And around 80% of those horses affected had ulcers in the front section of the foregut, the pars nonglandularis (caused by poor diet/lack of sufficient forage), with 20% of the horses ulcers' in the back section of the foregut, the pars glandularis (caused by stress), just before the exit into the small intestine via the pyloric sphincter (hence why glandular ulcers are also referred to as 'pyloric' ulcers).

The researchers tried many solutions, ranging from different medications to different feeds, and to their utmost surprise they found the best therapy - and preventative - was ... to feed hay. As simple as that. They also found a major cause - that not having access to hay for at least 4-hours or more, especially overnight when stabled (sadly a practice at many professional yards), caused inflammation of the stomach mucosa lining which then developed into gastric ulcers. And when you have inflammation at cellular level, along with red-raw pain, this spreads a whole lot further than just the injurious site, thanks to the nerves in the body which are everywhere, and tell each other everything. *Oct'21 - Edited to add: studies now recommend removing all starch wherever possible when feeding ulcerogenic horses - starch creates fermentation in the stomach which creates volatile acids, which makes the ulcers a lot worse.

This constant hay-feeding makes perfect evolutionary sense when you look at the historic, normal function of a horses' stomach/foregut, because evolution has made the horse a constant trickle feeder - horses have to have constant access to forage so they can feed 24-hrs/day - it's in their DNA to eat all day and all night. This means the stomach is normally always full of feed, with the horse constantly chewing, constantly creating saliva to buffer the acid pH balance gradient, with it being a higher, more alkaline pH at the entrance of the stomach - a pH of around 6-7, dropping down to a more acidic 3-4 pH before the feed exits into the small intestine via the pyloric sphincter.

This pH gradient isn't meant to change, so we shouldn't ever get a stronger acid reading in the front section of the foregut, but this is exactly what happens when the domesticated horse runs out of hay/roughage for a prolonged period of 4-hours or more. The stomach becomes empty, but the acid-secreting glands in the back section of the stomach keep on producing hydrochloric acid. This is unlike other mammals, i.e. dogs and us humans, where our stomachs are used to not eating for long periods, so the acid production shuts down. Not so in horses - stomach acid is continually being produced, and the scientists found really aggressive pH values of 1.3 in the empty stomach compared to a normal 3-4 value.

Under normal circumstances, the horse can cope with these severe levels because the acid section of the stomach wall has a thick mucosal layer to protect it, so normally, the acid doesn't make direct contact with the epidermal cells of the stomach wall. However, this isn't the case for the front section of the stomach, which only has a very thin mucus layer because, being a typical non-acidic area, a thicker layer isn't needed.

So, back to that now empty stomach, and the acid secretory cells continuing to produce acid at a much stronger pH value, and now - oh-oh - the horse physically moves. The movement cues acid splashing up onto that less-protected front section of the stomach where it doesn't normally belong, right onto that thin cellular membrane. Result? Remember - its pH level is now at a serious 1.3, so we're talking serious burn, instantly burning through the thin mucus layer and straight onto the epidermal cells, triggering major pain, a major inflammatory response, and finally, ulceration. And all because of wrong feeding management, letting a horse run out of forage. Empty stomach = stomach front-section ulcers. Full stop.

The simple solution? Don't ever let a horse run out of forage so feed a horse hay 24/7. The horse constantly chews, this creates saliva which buffers the acid from the bicarb in the saliva, the pH values and gradient rebalance, the mucus layer regenerates and the gastric ulcers heal. Simples.

The other 20% of horses

So now to the other 20% of horses who have ulcers in the acid-producing back area of the stomach, and it took the scientists longer to find out why these occurred. The theory was that with this back area having a very thick mucus layer, no matter how aggressive the acid gradient was, the acid shouldn't penetrate the mucus layer to the cellular tissue underneath. Wrong. Cut to today, and now we know the cause of the why this happens - stress. Ongoing, long-term, chronic stress. Here's the Why&How.

Stress is a perfectly normal reaction to a perceived threat - the fight/flight response kicks in and the natural instinct for a horse is to run away. In order to run, fast, the muscles need blood, so cortisol, the main stress hormone, shuts down various non-essential parts of the body to divert extra blood to where it's needed to deal with the crisis, i.e. the muscles to run fast, and the brain to focus on that threat.

When a horse is relaxed, roaming outdoors and eating, digestion is well-supported with blood for its energy to digest, but cue a threat and this changes dramatically - I mean, who needs digestion when there's a tiger on your tail? So, the non-essential blood vessels dilate, the essential blood vessels expand, and extra blood is pumped into the muscles to outrun the threat.

Once safe, the body calms down, rebalances and everything returns to normal, usually within the hour, but when a horse is under constant stress, i.e., lack of movement, isolation, stabling, herd stressors, sudden changes, competition, psychological stress from travel and training, breeding/pregnancy, worming, parasites, medications, vaccines, viruses, injury ... you name it! (and just to add, all human-driven) ... that stress On-Button stays switched on, so the blood supply to the all-important stomach remains disabled, as in switched to Off.

This disabling occurs around the pyloric sphincter, just before the entrance into the small intestine where the thick mucus layer resides, so with a degraded blood supply, this thick mucus layer degrades as well. This is what the study discovered, that the longer a horse was under constant stress, the thinner this area of the stomach mucus layer became, exposing the epidermal cells of the stomach wall membrane to a seriously aggressive pH 1 acid. Again, cue serious burn, serious pain, destruction of the mucus layer, a major inflammatory response, and ulceration.

Gastric ulcers in this back section of the stomach are notoriously harder to treat because the acid is so severe - as strong as a car battery - and the pain is major-league chronic, which in itself leads to further debilitating stress, so we end up with a vicious - literally - cycle. The continued pain/stress keeps the cortisol flooding the body, continuing to switch off the body's non-essential functions and diverting the blood to the survival organs, so the protective thick mucus layer can't regenerate. Despite doing all you can to remove the external stressors, this particular stress is internal.

If the painful fire isn’t put out, the continuing inflammation of a system, especially the digestive system - the system upon which health completely relies on to fuel the very survival of the organism - triggers a cascade of further stressful cellular disruption on the body as a whole, because it’s furiously trying to work overtime in an attempt to get some form of balanced homeostasis back, as in maintain a relatively stable internal state despite changes in the world outside - aka, balance. All living organisms, from plants to puppies to people, and our horses, need to keep their internal environment regulated to process energy and ultimately, er, survive.

So meanwhile, while the immune system and other organs are trying to pick up the slack from the non-functioning gut, they themselves become overburdened, exhausted and sluggish, and eventually the whole organism starts to crash. For a healthy balanced body to be firing on all cylinders, we need that gut to be functioning properly - quite simply, life-force, the body's vitality, depends on it.

Again, hay can be a life-saver here, as chewing relaxes the horse and releases endorphins - happy hormones - a chewing horse is a happy horse! So the more the horse chews, the happier it is, which eventually curtails the production of the stress hormones. However, these particular glandular/pyloric ulcers need to be addressed on a greater therapeutic level.

The stats make for sad reading - this doesn't happen in our wild horses as they're always moving, always eating, and don't have the same stressors as the domesticated horse, other than an occasional predator that they can usually outrun. These days in our domesticated world, there's a 50% ulcer syndrome showing in regular pet horses; sports horses up to 90%. Even foals are showing up to 80%, so it's now a critically widespread problem.

Gastric ulcers can also be a reason behind faecal water -

  • horses may not drink enough water in winter because cold water causes pain on the ulcerative site
  • horses don't like to be ridden when they have ulcers because of the pain
  • horses may struggle to eat stemmy hay or go off their feed because of the discomfort

All signs that there may be gastric ulcers. They're constantly in pain so always check. For more information on feeding our horses how they should be fed, see our Why What We Feed Has To Be Right page.

Now to the drug companies

So, we think our horse has got ulcers, and the vet has likely said that there's (allegedly) too much acid going on (but hopefully we've already dispelled that myth because ... The-Acid-Is-There-For-A-Reason!). Long an short though, we need these darned ulcers fixed.

Meanwhile, behind the scenes the drug companies are preying upon our vets - and GPs, because us humans get ulcers too for the very same reasons - insisting that it's all about too much stomach acid, and hooking them into a nice, fat, financial alliance that they should write expensive prescriptions for their wonder-drugs for us mortals to either swallow, or to give to our horses, to quell that acid burn.

Never is there a mention that there might be an actual reason behind why there’s acid burn or ulcers; never a suggestion that the curry we ate might have been a bit over the top, or for our horses, no mention that it's likely to be the lack of constant hay or the haylage, or he alfalfa, soya or any of the other poor-quality pro-inflammatory equine gut-damaging ingredients found in our ultra-processed feedbags, that are known to cause gut sensitivities and damage the gut environment, and therefore Should Be Avoided. (Show me any vet that asks an ulcerogenic horse's owner what their diet was ...)

Truth is, those wonder-drugs not only fail to address the actual causes of acidity and/or ulcers (stressors and/or inappropriate feed) but put our horses - and us - at further digestive health risks.

Here we go - controversy time. If I was to say to you that by feeding acid-stopping drugs to our horses, it might cause ...

  1. Increased negative bacterial overgrowth.
  2. Impaired digestion causing colic risk.
  3. Significant nutrient malabsorption.
  4. Decreased resistance to infection.
  5. Kidney disease.

... what would you say?

I had originally intended to cover the How&Why of all these side-effect issues here, but as I started to write I realised it would make this page 12-ft long. So I’ll just go with what I feel is the most important for us horse owners, specifically impaired digestion, impaired gut flora syndrome, and impaired nutrient absorption, because let's face it - these alone mean one very sick horse.

So, with so much new research coming out about the damaging side-effects of acid-stopping drugs, let's just dive straight in and talk Proton Pump Inhibitors, aka PPIs, aka acid-production blockers, aka ... a vet's go-to drug of choice for equine ulcers.

Proton Pump Inhibitors - PPIs

When it comes to our horses, the acid-blocking drug of choice is generically known as a PPI, aka a Proton Pump Inhibitor - you know the ones, the ulcer drugs that all end in ‘zole’. It's also probably useful to understand what a proton pump is, so here we go with a quick explanation.

Potential Science Alert 🤓 - A proton pump is a natural bodily-part of every mammalian body out there; it's an integral membrane protein essential for cellular energy production; their vital function is literally to 'pump' an electrical instruction across a biological membrane, to trigger an essential function for balanced homeostasis to exist. Hope that wasn't too science-y, but basically they're very clever, and very essential.

Back to the equine foregut, and its own proton pump's instruction is to produce - you've guessed it - digestive acid, so by feeding an inhibitor of the proton pump will reduce the production of acid. It does this by blocking the enzyme in the wall of the stomach that produces acid. Hence the name, Proton Pump Inhibitor, aka PPI.

Let's delve a little deeper ...

... and what they do to the body.

PPIs are a group of drugs whose main action is a significant, and long-lasting, reduction of stomach acid production; they are the most potent inhibitors of acid secretion available. Vets prescribe them for equine ulcers because on the surface, they provide fairly quick relief and you can't argue with that. Your horse has ulcers, and half a ton of p****d-off horse in pain is no joke.

So, the powerful chemicals in the ‘zoles’ switch off the proton pump which secretes the stomach acid, so in theory, by turning the acid off, there’s no more burn, and ultimately that's the goal, to stop the pain, and make your horse both comfortable and safe to be around again. I get it. Of course this is what we want - our horse out of pain so we can cuddle them - not to mention ride them - again. What's not to love?

Plenty, as it happens. Here's the reality - behind the scenes PPIs drastically mess with the body's biochemisty, which is never good news. Quick confession - in case you hadn't guessed, I'm not a fan of PPIs. At all. Because they cause untold damage further down the line, and worse, their effect on the ulcers doesn't last long because just about every related client enquiry I get says their horses' ulcers came back. 🤨

So now let's get to the rub. Although previously assumed to be safe, studies as far back as 2010 have shown that PPIs have numerous side effects, including causing a further altered gut environment and impaired nutrient absorption, to an increased risk for kidney disease and neurological impairment - google it; run a search on PubMed. or Scholar.google.com. And here’s the irony – remember, those ulcers are there because the gut environment is already altered, due to either inappropriate feeding or stress, or inappropriate feeding which causes stress, which then destroys the rest of the gut function etc etc.

These essential, clever, natural, proton pumps in the body are a highly complex, essential part of the mammalian physiology, and ... they’re not just limited to the stomach. They’re present in just about every cell in the whole body, so let's quickly talk cells for a moment. Other than red blood cells, all of the body’s cells have a mitochondria (probably my favourite M-word which I use a lot on this website), which is the energy-producing furnace in the middle of every cell. Picture a coal fire on a steam train being constantly fed coal to create the heat to generate steam, which produces the energy that makes the train move? That coal fire is the train’s ‘mitochondria’.

Sorry, bit of a Science Alert again 🤓 - So, the body’s cellullar mitochondria metabolise (burn) carbs, fat, chemicals, minerals – you name it, the mitochondria burn them, to produce specific energies to make the body’s various systems operate and do what they're meant to. And how do they do this? They trigger this thing called a proton - a source of electrical instruction which is pumped across a membrane that’s specifically harnessed to form ATP, the body’s main storage form of energy. I know, a bit confusing, but all explained in our Fix the Cell to Get Well page if you fancy a bit of biology ... there are even funky images! Sorry, I get a bit nerdy when I talk about this stuff as I find it truly fascinating ... 😉

Back to it and now here’s another rub - without an efficiently functioning proton-pumping system pumping their messages, the body must rely on anaerobic systems for energy production, which will lead to rapid fatigue.

So, back to the proton pump in the stomach, the pump to make the acid-secreting cells secrete the acid, aka the parietal cells. The chewed food mixed with saliva (a bolus), travels down the oesophagus towards the stomach, collecting beneficial bacteria and a few digestive enzymes on the way. This very action triggers the foregut’s proton pump to stand by, ready to release the stomach acid to start the digestion process.

And in case you haven't read the bit about digestive enzymes getting involved (main Gut System page) ...

Now we need to bring food proteins into the mix, or not, as it happens, which is really, really bad

... when the food bolus arrives in the stomach, it’s immediately mixed with the protein-digesting enzyme, pepsinase, the precursor to pepsin, the protein-digester - I say precursor, because pepsinase needs to be converted to pepsin in order to work, and the converter is ... you’ve guessed it - stomach acid! So, without the acid, pepsinase doesn’t become pepsin - depressed acid levels means depressed pepsin levels. Which is really important because ...

... This means that proteins won’t get broken down into their crucial-building-blocks-for-the-body amino acids and peptides. Which means a deficiency of those essential amino acids, which creates its own significant side-effects, i.e. depression, anxiety and exhaustion. Sound familiar in your horse? Already we can see the first negative side-effect of giving our horses a PPI; inhibiting the release of stomach acid from the parietal cells impairs one of the most vital digestive functions - the onset of protein digestion.

And the worst bit? Undigested proteins can have a profound effect in the whole digestive process. If they remain large and undigested, they can end up in the hindgut (where proteins should never venture) and cause a very major, very severe, colic risk. Seriously.

Let's move on to further effects of PPIs (and we haven’t even got to what else happens in the digestion process). Research shows that – more bold type needed - PPI’s also bind to the many other proton pumps in the body (https://www.ncbi.nlm.nih.gov/pubmed/1647821). This really is significant. This binding to the body's other vital instruction-giving proton pumps is essentially irreversible - PPIs continue to inhibit all the other proton pumps until the body’s own master antioxidant, glutathione, which can only be made by the body, has to step in to facilitate disassociation. This means that stopping feeding PPIs won’t stop their damaging effects immediately, meaning that weaning the body off PPIs is much more complex than we think.

However, getting back to digestion, the Big Issue for me with the PPIs, the 'zoles' of the world, is that the foregut needs its acid to perform digestion, and feeding PPIs stops this absolutely crucially critical function.

A bit more about digestion

As explained earlier, the foregut is all about pre-digestion, as in kick-starting the digestion process off - it provides the environment, and the muscle, to churn that bolus from solid chunks to a soup-y liquid (chyme) of broken down food, saliva, acid and pepsin, to enable a smooth passing of the chyme digesta into the small intestine where it meets more digestive enzymes. A bit like a pre-wash programme on our washing machine before the main cycle kicks in. Without acid, this pre-wash won’t happen. A quick reminder - the stomach acid works with digestive enzymes at the pre-digestion process to start the breakdown of the food. If the acid’s switched off at the beginning, the digestion process is impaired from the get-go.

The perfect world of digestion

Let’s break the foregut digestion down into easy stages and you'll see just how important the acid's role is. Here's the full gory details of how a perfectly functioning digestive system works, from the second food goes into our horse’s mouth:

  1. Food is chewed, causing three pairs of salivary glands to release saliva. The acid-buffering agent in saliva, bicarbonate, buffers and protects the mix of chewed food and saliva (bolus). Saliva also contains small amounts of amylase, the first of many crucial digestive enzymes, which starts pre-digesting carbs.
  2. Once the bolus is swallowed, it travels down the oesophagus where various beneficial flora reside, ready to jump into the mix to start their own important digestive role.
  3. The bolus arrives in the foregut, where it meets lactic acid bacteria which start to pre-digest starch, and pepsinase which is converted to pepsin when it meets the stomach acid. (PS - I know I say all over this website that lactic-acid bacteria are disastrous for the equine intestinal gut environment. They are. But - they're present to a degree in the stomach, usually brought in off grazed forage, but are then usually destroyed in the stomach acid disinfecting rinse. Unwanted lactic-acid bacteria ending up in the intestines is simply caused by an over-excess of ingestion, i.e. via haylage, and once in there, they then multiply as all bacteria does, leading to the dysbiosis/leaky gut domino effect).
  4. Back to it, and the muscular wall of the foregut is now churning, mixing the digesta thoroughly with the stomach acid and pepsin. Together they initiate the process of digestion and degradation of starches and proteins (amino acids).
  5. Once the foregut has done what it needs to, the pepsin and acid digesta mix is now a soupy mix called chyme, and is pushed through the exit valve into the small intestine, where a team of other digestive organs get involved. First up, the duodenum signals the liver to release bile to break down any fats. Next, the pancreas secretes further digestive enzymes (and insulin) to continue the process of enzymatic breakdown of the proteins, fats, starches and sugars. The pancreatic juices also contain some alkali and further bicarbs to provide more buffering of any acid that left the stomach, to help maintain an optimal environment in the intestine for those important digestive enzymes to function.
  6. Now the serious business of digestion starts taking place, as the small intestine also has its own digestive enzymes – as well as more beneficial bacteria - to continue the breakdown of those proteins, fats, starches and sugars.
  7. Finally, much further down the small intestine, when everything’s now broken down and assimilated, the nutrients are finally absorbed through the intestinal wall and carried off by the blood stream to whatever cells need the nutrients. This generally takes 3-4 hours, usually moving at a rate of approximately 30cm per minute.
  8. We should now only have the fibre remaining, which now comfortably passes into the large intestine for fermentation.

A perfect-world, perfect digestion scenario 😄 But now imagine how much longer digestion will take with the PPI effect; worse, they amplify the burden by overloading the digestive tract with undigested digesta - those large proteins mentioned above - which greatly increases the risk of colic, laminitis and acidosis. Introduce PPIs and you can see how, by switching off the acid secretion:

  • the acid level declines
  • the pH of the stomach increases
  • the structure of the digesta is impaired
  • enzymatic digestion is limited
  • nutrient absorption is impaired which drastically impairs health, wellness, and staying sound and active.

We might think we feed our horses well, but without the acid influence, they’ll end up under-nourished. We can feed the most nutritious diet imaginable, packed with vitamins, minerals and other essential nutrients, but if they’re not absorbing those nutrients that you’ve paid good money to provide, they won’t benefit from them.

As an example, let’s have a quick look at how this affects the important micronutrients. Decades of research have confirmed that low stomach acid reduces absorption of several key nutrients such as iron, B12, folate, calcium and zinc, with many reduced micronutrient levels also dependant on each other being absorbed.

And then there's our old friend SIBO

Acid is also the microbial contaminant disinfectant - switching the acid off causes pro-inflammatory bacterial to pass through unimpeded into the small intestine, and we all know what happens when this occurs! Here's the knock-on effect:

  • Over population of bad bacteria v. good bacteria causes mal-digestion of carbohydrates.
  • This in turn produces lactic-acid gas.
  • This gas increases the pressure in the foregut, causing the lower esophageal sphincter (LES) to malfunction.
  • The malfunction of the LES allows acid from the stomach to enter the oesophagus, thus producing the symptoms of acid burn.

So, when your vet says your horse has acid in the 'upper digestive tract (oesophagus), this is what's going on.

Bacterial overgrowth has a number of other undesirable effects, including inflammation, and as before, reduced nutrient absorption. Studies have confirmed that by suppressing stomach acid, PPIs profoundly alter the gastrointestinal bacterial population. Researchers in Italy have shown increased incidence of SIBO (small intestinal bacterial overgrowth) in 50% of patients using PPIs, compared to only 6% of healthy control subjects. https://www.ncbi.nlm.nih.gov/pubmed/20060064

To summarise the PPI effect

Just say No! PPIs drastically impair digestion and nutrient absorption. It’s a product I simply cannot endorse. There is another way, and it’s healthy, natural, and plant-powered! Plus lifestyle factors - removing stressors and relooking at the feed regime.

Update - 14.4.21

"Recently more importance has been placed on the co-administration of NSAIDs and the inhibitors of gastric acid secretion, such as proton pump inhibitors and histamine H2 receptor antagonists, in determining a significant alteration of intestinal microbiota composition and exacerbating NSAIDs enteropathy [21,66]. PPIs determine hypochloremia causing abnormal growth of bacteria that can colonise the small intestine causing SIBO (Small Intestinal Bacterial Overgrowth) with increased bacterial translocation [67,68]. Wallace et al[69] in fact reported that PPIs, in particular (the most commonly prescribed 'zole', the name of which I can't say without risk of litigation) resulted in significant dysbiosis, with both a substantial increase in Gram-negative bacteria and a significant reduction in the proportion of Actinobacteria (mainly Bifidobacter ssp.) in the jejunum."

Read the full report here: Utzeri E, Usai P. Role of non-steroidal anti-inflammatory drugs on intestinal permeability and nonalcoholic fatty liver disease. World J Gastroenterol 2017; 23(22): 3954-3963 [PMID: 28652650 DOI: 10.3748/wjg.v23.i22.3954]

The Ulcer Fix-Kit

On a positive note, this can all be reversed, and either way, the fix-kit is the same.

First up, we need to alleviate the agonising pain the horse is very stoically experiencing, which will also naturally help reduce the stress levels if the pain’s gone. So:

  • It's our DuoBute blend for a couple of weeks, which is our completely natural, organic, no-side-effects herbal pain/anti-inflammatory support.
  • If there’s also glandular - stress-caused - ulcers, we also need to stabilise the adrenal (stress) function with a 1-month (1kg) course of our StressTonic.

Now to the fix-kit itself and it’s nice and straightforward. Those ulcers won't heal themselves until the protective mucilaginous layer in the GI tract has regenerated, so:

  • We need a 1-month course of our UlsaTonic blend, a gut-cleansing blend of organic herbs with anti-ulcerogenic support.
  • Alongside this we feed our GutAminos which start repairing the cellular protein damage to the intestinal wall membrane. The GutAminos may take a couple of months so assess as you go – in humans it can take up to 3-months but we tend to eat a much more varied – and potentially damaging - diet, from processed, refined, artificial junk-food ready-meals to fiery curry take-outs, sugary carbs and gluten, all washed down with an array of fizzy drinks or alcohol, so the human gut wall membrane often needs a bit more help 😉

Feed the UlsaTonic in the a.m feed with the GutAminos; DuoBute in the p.m feed alongside the StressTonic if needed.