Hot of the press!! Vet Services are very excited to have just purchased a gastro-scope! We are looking forward to now being able to offer this service on a day to day basis
A few things have changed since we last spoke – keep reading to find out what the up to date research is saying!
Gastric ulcers (stomach ulcers) is a hot topic! Gastric ulceration is a somewhat confusing syndrome – the syndrome can have a multitude of clinical signs, ranging from subtle performance issues, behavioural change, picky eating, to weight loss and colic. There is also a multitude of products on the market which claim to help with ulcers, not all being equal. There is also a lot of misinformation circulating!
Gastric ulcers have been proven to have significant effects on performance
- Behavioural issues, training issues, issues under saddle
- Indirect effects on performance that relate to feeding and reduced recovery rates
- Direct effects on performance
- Reduced stride length
- Shorter time to fatigue i.e. they fatigue quicker
- Reduced maximum oxygen uptake
How do you know if your horse or pony has gastric ulcers?
Until recently, the only way we could diagnose ulcers was on behavioural and clinical symptoms – this includes an array of symptoms that can be associated with ulcers, including; poor coat, difficulty gaining weight, recurrent colic, temperament or behavioural changes, reduced appetite, picky eating, girthiness, sensitivity around the abdomen, poor performance, crib biting, etc. etc.
This is all and well, as all of the above can be caused by ulcers; however recent studies have shown the accuracy of these ‘classic symptoms’ to be poor in the diagnosis of ulcers. Tolerance and outward signs of gastric ulcers will vary immensely between horses – some with mild ulcers may show obvious outward signs, whereas other stoic horses (or ‘silent suffers’) may only show mild and transient symptoms (e.g. nervousness, picky eating), despite having severe ulcers.
Some non-veterinary practitioners use the presence of reactive acupuncture points to diagnose ulcers. While this can raise suspicions of their presence, it is nonspecific and has not been confirmed as an accurate or valid diagnostic test for ulcers
Gastroscopy – the use of a 3 metre endoscope to directly visualise the stomach lining, is the only definitive and accurate method to assess the presence and severity of gastric ulcers – most importantly it is the only way to diagnose between the two separate diseases – see below
Gastroscopy (stomach scoping) has moved the diagnosis from a guessing game, to black and white.
It is now recognised that there are two distinctly different diseases when it comes to gastric ulcers
- Equine Squamous Gastric disease (ESGD) – the originally described disease since the 1990’s
- Equine Glandular Gastric Disease (EGGD) – a more recently identified disease and less well described.
These diseases have previously been assumed to be related, however this is incorrect! They vary in their risk factors, their causes, their prevalence, affected population, and their response to treatment
- They live in the same apartment but have nothing to do with each other!!
Long term management of each disease is different – gastroscopy is essential to formulate a plan for your horse
How common are ulcers?
The prevalence of each type of gastric ulcer varies with breed, the type of exercise the horse does, and how they are managed.
ESGD – In thoroughbred racehorses, it is reported that 80-100% of horses in training are affected. Rates of 64% in sport horses, 93% in endurance, and 54% in pleasure horses have been reported in the literature. Ponies who are on feed restriction for weight loss are at a high risk if they are not able to graze continuously.
EGGD – an average prevalence of 50% across all types/disciplines
What causes ulcers?
The horse’s stomach is divided into two main areas, each with a different lining (mucosa). The top part, called the squamous or non-glandular portion, has a lining similar to skin, lacking adequate defence against stomach acid. The bottom section is the glandular area, which is responsible for acid secretion. It secretes a thick layer of mucous, as well as bicarbonate, to buffer this acid and protect its lining.
Horses, unlike humans, secrete gastric acid continuously. The horse evolved to graze high fibre feed for around 18 hours per day – when horses have continuous access to roughage, the presence of feed in the stomach buffers the acid, and acts as a ‘matt’, protecting the vulnerable squamous portion. Chewing causes saliva to be produced – this is high in bicarbonate which also helps to neutralise acid. Exposure to acid (acid splashing), is thought to be the cause of ulcers in the squamous part of the stomach. High starch feeds (grains) also create more acidic conditions, than roughage or fat.
When horses exercise, the pressure in the stomach increases, and causes acid to splash onto the squamous mucosa, causing damage. The more strenuous the exercise, the more pronounced this effect is. Added to this, is the fact that many horses have traditionally been held off feed before exercise, so there is more acid, and less feed and saliva to neutralize it. Even when horses aren’t exercising, periods of feed restriction put them at an increased risk of ulcers.
The type of diet can contribute to ESGD risk. High starch, grain diets increase acid production and can indirectly injure cells in the squamous part of the stomach, as well as being lower in fibre and overall bulk. Higher fibre feeds are eaten more slowly, and form a ‘mat’ that sits on the acid to reduce splashing. Lucerne is a particularly good feed because the high calcium content assists in buffering the acid.
It is believed that an upset of the mucous barrier is the root cause of glandular lesions (EGGD) – see below risk factors
Any factors that increase stress levels, for example, transport, box confinement, competition and musculoskeletal pain, all increase the likelihood of ulcers developing.
Both types of stomach ulcers are essentially management diseases – modern management of horses is very different to what they were ‘designed’ for!
Risk factors for Gastric Ulcers
Equine Squamous Glandular Disease (ESGD)
- 3 MAIN RISK FACTORS
- Increased carbohydrate
- Inadequate roughage
- Exercise amount (total volume of exercise)
- How you exercise matters
- Increased risk with increased intensity
- Increased risk with increased duration
- Timing of feeding and exercise is important
- Pasture turnout is unlikely to be protective
Equine Glandular Gastric Disease (EGGD)
- NOT a disease of diet
- Not having scheduled rest days very important
- No animal to animal grooming (covers on 24/7!)
- No paddock mates
- Concurrent disease – e.g. musculoskeletal pain
- Warmbloods are at higher risk
Why not just do a treatment trial??
The cure rate for ESGD with a 4week treatment of omeprazole is around 70%
The cure rate for EGGD with a 4 week treatment of omeprazole alone is around 25%. Glandular ulcers can take 6w to 6m to heal – treatment for longer periods, and adding sucralfate, is required.
For EGGD an initial improvement in the clinical symptoms is often followed by a fast relapse if the ulcers were not fully healed when the treatment is stopped
It is worth noting that 25% of horses have reduced uptake of the omeprazole (antacid) drugs – these horses are the ones that just don’t seem to improve with normal treatment – identifying these non-responding horses is essential for improved outcomes
An accurate diagnosis of the correct type of stomach ulcers is essential to getting a satisfactory outcome, and the best ‘bang for your buck’
It is worth noting that Gastroscopy can be very useful in differentiating between gut pain and true behavioural issues – for those cases that are not obviously clear cut. Based on variable cure rates, treatment trials alone can sometimes lead to confusing results!
Treatment and Prevention of Gastric Ulcers
This is a huge topic (an article in itself) and needs to be tailored to individual horses/properties. Accurate diagnosis is essential – please call the clinic and chat with your vet about formulating and plan for you and your horses
Mike Fitzgerald BVSc.