Gastric ulceration in Horses

Two adult horses presented to PHD Veterinary Services this Fall/winter for very different complaints yet the same disease process. Horse #1 was a 10 year-old gelding that presented for the complaint of rearing under saddle and refusing to go forward. Horse #2 was a 5 year-old mare that presented for the complaint of recurrent low grade colic after eating. A gastroscopy was performed on both horses and both horses were diagnosed with gastric ulcers. In Figure 1, the area of ulceration is within the blue circle and the ulcerated tissue is highlighted by the red arrows. The ulcers in Figure 1 correspond to the horse which was rearing and the ulcers scored a 3 out of 5 with 5 being severe. In Figure 2 and 3, the ulcers appear less severe (score 2/5) and correspond to the horse that was demonstrating abdominal pain after eating. Interestingly, the gastric ulcers in the horse that was rearing under saddle appear worse than the horse with recurring symptoms of colic.
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Figure 1

Figure 2

Figure 3

 In Figure 4, a "normal stomach" is imaged through gastroscopy. The horse's stomach can be divided into the glandular stomach (darker red tissue) and the non-glandular stomach (lighter tissue). The junction of the two types of tissue (yellow arrows) is called the margo plicata. Most gastric ulcers in horses occur at the margo plicata and in the non-glandular stomach immediately adjacent to the margo plicata.

Listed below are a list of clinical symptoms which can fit with gastric ulcers in horses:

1- Recurring colic
2: Weight loss and failure to thrive
3: Poor performance
4: Sudden change in behavior
5: Unwilling to go forward
6: Rearing under saddle
7: Increased sensitivity to brushing/touching of abdominal and flank area
8: Repeated straining to urinate: parking-out for geldings and tail flagging for mares

The take home message is that gastric ulcers can present in many different ways and should always be considered when evaluating horses for performance/behavior issues.

Gastric Ulceration causing poor performance in a horse!!

A 12 year-old event horse presented for poor performance that was best described as unwilling to "go forward". The gelding was evaluated for lameness and was described as sound. The gelding maintained a good appetite and there were no signs of colic behavior reported. A gastroscopy was scheduled and the owner was instructed to fast the horse for 18 hours. When the gastroscope was passed into the stomach a large volume of fluid was present mixed with feed material. Approximately 3 liters of fluid was removed from the stomach in order to visualize the non-glandular compartment. The remaining fluid was filled with feed material and was not removed. However, a clear pattern of non-glandular ulceration was noted throughout the exposed stomach wall (Figures 1-3).

 

 

Figure 1

 These ulcers appear full thickness thru the layer coating the inside of the stomach and are evenly spread through out the stomach. We were not able to visualize the glandular stomach or the pyloric region which may be abnormal in this horse. The fact that the gelding's stomach was filled with fluid and some feed after 18 hrs of fasting would suggest a delay in gastric emptying which may be associated with inflammation of the pyloric region. As such, this gelding will be treated with omeprazole for the appropriate period of time. In addition, the horse will be treated with a stomach coating medicine for the first 48 hrs to alleviate any immediate discomfort due to the ulcerations.

Figure 2

 This case presents yet another example of the types of clinical signs that may be associated with gastric ulcers. Classically we consider horses that have sings of colic, weight loss, poor appetite or failure to thrive. However, in my expereince, horses with gastric ulcers may present in many ways and this condition should be considered on our lists of differentials!!

Figure 3

Pyloris of a Horse of course!!

The endoscopic images in the following figures are of a horse's pyloris. This is the portion of the stomach that creates a valve and allows gastric fluids and contents to enter the small intestines. The very first region of the small intestines is known as the duodenum. In Figure 1, the pyloric sphincter is open and a small amount of feed material is noted around the edges of the sphincter. In Figure 2, the pyloris is nearly completely closed. The movement of material through the pyloris is controlled via rhythmic contractions or peristalsis of the stomach's muscular wall.

Figure 1

Figure 2

In Figure 3-6, there are very important abnormalities noted around the pyloric sphincter. In Figure 3 and 4, there is evidence of active bleeding from ulcerations around the pyloric sphincter! These ulcerations are likely to be a source of significance discomfort in the horse and would contribute to signs of gastric ulcer disease. It is possible and common to examine a horse's stomach and miss these lesions if the horse is not properly fasted prior to the gastroscopy and the pyloric sphincter is not visualized. This can be quite difficult in some equine patients!! The pyloric sphincter essentially controls the rate of gastric emptying hence any inflammation in this area will likely SLOW the rate of gastric emptying and result in an abnormal build-up of gastric fluid/content within the stomach.

Figure 3

Figure 4

 In Figures 5-6, there is a significant amount of hyperemia around the pyloric sphincter which corresponds to active inflammation. The degree of clinical signs may vary significantly from horse to horse however it is highly likely that horses with these types of lesions will have clinical signs consistent with gastric ulceration and WILL require the proper medical management! These type of lesions may be caused by excessive use of non-steroidal anti-inflammatory agents such as banamine and phenylbutazone. Diagnosis is dependent on a COMPLETE gastroscopy and I typically recommend a follow-up gastroscopy after treatment to verify complete resolution of the pyloric sphincter ulcerations!!

Figure 5

Figure 6

Gastric Ulcers in a horse

The endoscopic images below are from a teenage gelding that presented for a complaint of aggressive  behavior while grooming. The gelding was not displaying any classic signs of colic nor was there a decline in food intake or a report of weight loss. When the stomach was examined, several bleeding ulcers were noted surrounding the pyloric sphincter. This region of the stomach includes the passage from the stomach into the small intestine. The gelding was treated with 45 days of Gastrogard and returned to normal behavior.

 The important message from this case is that gastric ulcers in horses can present like most anything! Classically, they present as low grade colic associated with feeding plus or minus weight loss. However, in my experience clinical signs associated with gastric ulcers have included poor performance, dull hair coat, excessive water intake, sour behavior under saddle, aggressive behavior while being groomed, colic, parking out, frequent posturing to urinate, teeth grinding, and weight loss.

I strongly recommend a gastric exam which includes visualization of the pyloris to determine if gastric ulcers are the source of the clinical complaint. This involves 24 hrs of fasting and a trained clinician with a 3 meter gastroscope. If ulcers are discovered, the only treatment proved to be effective is Gastrogard medication for at least 30 days! I typical recommend 30 days of a full dose followed by 2 weeks of a half dose.