Preventing Colic in Horses

Colic.

It's one word that strikes fear in most horse owners — and for good reason! A horse with no outward signs of distress can find themselves in trouble just a few hours later.

With colic in horses causing significant issues, you may be wondering if there are ways of preventing colic. The good news is yes. With a little work, you can help keep your horse happy, healthy, and hopefully colic-free.

First, let's take a quick look at what colic in horses is and why it happens.

What is Colic?

From horses to humans, colic is a broad term that refers to any abdominal pain.

The severity of colic in horses depends on what is causing it. It could be spasmodic colic (or gas colic) caused by excessive gas in your horse's digestion. Or it could be impaction colic with several different causes that are entirely disrupting your horse's digestion.

The severity of colic also dictates a veterinarian's ability to assist. If caught early enough, it may take some medication and slow walks around the barn. If severe, it means going into surgery to remove the impaction.

If your horse is showing the below signs and symptoms of colic, call your vet immediately.

• Rolling or Wanting to Lie Down
• Lack of Appetite
• Lack of Defecation
• Lack of Normal Gut Sounds
• The Appearance of Being Bloated
• Pawing & Signs of Anxiety
• Increased Heart Rate (normal is 28-44 beats/minute)
• Profuse Sweating 

Colic is quite common and is a broad term. But, there are some things you can do to help reduce your horse's risk.

Tips for Preventing Colic in Horses

Like most things in the world, colic is not 100% preventable. But, you can go a long way in helping prevent severe colic in your horse.

Stay Consistent With Feed, Portions and Times

A potentially common cause of colic is a sudden change in diet, like food type or portion sizes. While changes in diet are sometimes necessary, it's important not be in a constant state of change.

During these shifts, it's best to switch the diet gradually over the week with incremental increases and changes. Small changes allow your horse's digestion to become accustomed to the new grains and food.

Keep Your Horse Moving and Active

A moving horse is a happy horse. And that unrestricted movement during turnout allows a horse's digestion and intestines to stretch out and do their jobs.

With each step your horse takes while socializing or grazing, the food in their gut is moving as well increasing the rate of breakdown and mobility in their system. A horse that is kept in a stall at all times, will have a hard time moving enough to help boost their digestion.

Always Have Fresh Water for Your Horse

Like moving, water helps your horse's digestion, and with preventing colic.

When a horse (or any animal) becomes dehydrated, digestion becomes harder and more taxing on the animal's system. A horse that is turned out or kept in the stall without access to clean water is at higher risk of impaction, one of the more severe types of colic in horses.

Preventing colic in horses isn't always possible, but the above tips can go a long way in helping keep your horse (and their digestion) happy. Have questions? Think your horse is at risk for colic? Give us a PHD Veterinary Services in Florida a call at 352-258-3571.

IIeal Hypertrophy in a Horse

A 10 year old Paso fino mare presented for recurrent colic for several months duration. The mare had a long history of being a "hard keeper" but in the past 3-4 months had begun to colic after each feeding. The mare was fed a diet of senior feed plus free-choice coastal bermuda grass hay. The mare was referred to PHD Veterinary services for a gastroscopy (stomach scope). The mare presented with a body condition score of 3 out of 9. The client reported that the mare had a good appetite yet shortly after eating, the mare would develop signs consistent with abdominal discomfort! The gastroscopy was normal therefore we opted to ultrasound the mare's abdomen.  In Figure 1 there is a cross-sectional image of a loop of intestine (black circle) that is grossly abnormal. The lumen (center) is completely filled in with soft tissue(grey area). The filled in center in Figure 1 corresponds to thickening of the small intestine which likely results in delayed passage of ingesta. Interestingly, there was only 1 very distinct area of the small intestine that scanned abnormally thick. However, there were several loops of small intestine that were dilated and had diminished peristalsis (Large black circles in Figure 2).

Figure 1

Figure 2

The ultrasound findings were consistent with a focal area of thickened small intestine and a large area of dilated small intestine. The dilated small intestine were likely "up stream" from the thickened small intestine and were as a result of partial obstruction of the thickened small intestine. Based on these findings, the mare was referred for abdominal exploratory surgery. During the abdominal exploration, a very thick region of the small intestine was identified. This region corresponded to the ileum which is the very final section of the small intestine. Approximately 12 inches of ileum were grossly thickened resulting in minimal lumen formation for passage of ingesta (Figure 3). Normally, the ileum is a wide-open tube as depicted in Figure 4!! Unfortunately, due to the severity of the condition, poor prognosis, and financial limitations, the mare was euthanized on the surgical table. Ileal hypertrophy has been reported in horses consuming coastal bermuda grass hay and it is theorized that some horses develop an "allergic" response to coastal hay resulting inflammation of the ileum and ultimately gross thickening. More commonly, colic symptoms associated with coastal hay is due to poor quality hay rather than ileal hypertrophy. However, any horse with chronic colic symptoms that is consuming coastal bermuda grass hay should be evaluated for this condition. 

Figure3

Figure4

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

Sand Impaction in a Horse

A six year old gelding presented for recurrent low grade fever and intermittent diarrhea. At the time of the initial exam the gelding was alert and showing no signs of discomfort. Vitals were normal and body temperature was 100.5 degrees.  A blood sample was collected for complete blood count (CBC) analysis and a rectal exam was performed. A large, firm structure was palpated along the left flank of the horse which was consistent with an impaction of the "pelvic flexure".  The fecal material removed from the rectum was partially formed and had a grainy feel to it. Several hand fulls of manure were placed in a rectal sleeve and the sleeve was filled with water (Figure 1).  A significant amount of sand was identified in the sleeve filled with water!

Figure 1

 The gelding was treated aggressively with water and mineral oil via a naso-gastric tube however; his condition worsened and he was referred to a surgical facility. Despite knowing that the gelding had a pelvic flexure impaction which is usually managed medically, the gelding was taken to surgery due to refractory pain. Abdominal exploration revealed an extremely large, firm impaction of the left colon which "bottle necked" at the pelvic flexure (blue arrow in Figure 2).  Discovery of such an impaction during surgery typically results in making a small opening in the colon wall and resolving the impaction. However, a small tear was discovered along the edge of the impaction which had resulted in fecal contamination of the abdomen. Prognosis was poor and the owners opted for humane euthanasia.

Figure 2

This case of sand impaction in a horse is sadly NOT uncommon in the state of Florida! The accumulation of sand within the colon of a horse is typically a result of poor pasture conditions and can develop very quickly. There are several "hair-pin" turns within the large colon of horses which create ideal conditions for the accumulation of sand and other debris. The pelvic flexure is one of those "hair-pin" turns and is one of the most common locations for colon impactions in horses. Unfortunately, once the sand impaction develops it is very difficult to resolve by providing oral medication such as psyllium (Figure 3)  and mineral oil (Figure 4).

Figure 3

Figure 4

The clinical indicators of sand accumulation in horses include intermittent diarrhea, low white blood cell count, fever and plus/minus colic. The sand is abrasive to the lining of the colon which results in diarrhea and sequestration of white blood cells in the colon wall. Horses with sand accumulation within their colons often have a week or month-long history of diarrhea! This is the time to treat the horse with sand clearing products. Once the horse becomes completely obstructed, surgery may be the only option to resolve the impaction. There are several products available to treat horses on a monthly basis as "sand clearing" products however once sand has accumulated within the colon, these products are not effective. They are more effective if used as products to prevent sand accumulation in combination with good pasture management! This condition is treatable but MUST be addressed when clinical signs first develop!!

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.

Phenylbutazone Toxicity!!

The yearling pictured below was being treated with Phenylbutazone for a severe lameness. The yearling weighed approximately 750 lbs and was being treated with 2 grams of Phenylbutazone twice per day for 2 weeks! Although the lameness improved, the yearling stopped eating and developed mild colic symptoms, severe oral ulceration (Figure 1) and eventually generalized edema. 

Figure 1

The serum levels of total protein and albumin were well below normal values and an abdominal ultrasound revealed severe edema of the right dorsal colon (Figure 2) . These findings were consistent with an advanced case of right dorsal colitis secondary to excessive phenylbutazone administration. Most often, when we discuss "ulcers" in horses we are referring to gastric or stomach ulcers. These types of ulcers may be caused by drugs such as banamine and phenylbutazone or are often a result of poor nutritional management. However, colonic ulcers may also be caused by such drugs, especially phenylbutazone. These types of ulcers are poorly understood and often difficult to diagnose in a standing horse. A typical history is that of a horse that presents for mild, recurrent colic, mild to severe diarrhea, ill-thrift, and a history of recent phenylbutazone treatment. Although the dose of phenylbutazone in this case was excessive, some horses appear to be super sensitive to the drug and may develop right dorsal colitis on an accepted dose of phenylbutazone. 

Figure 2

 Sadly, the yearling described could not be saved and was euthanized. A necropsy was performed and severe ulceration of the right dorsal colon (Figure 3 and 4) was discovered along with the marked edema of the colon wall (Figure 5). These large button-like ulcers cannot be detected via an ultrasound exam and would require surgical exploration of the colon to diagnose. The edema of the right dorsal colon wall can be diagnosed via trans-abdominal ultrasound and is secondary to the significant loss of serum protein. The protein is lost through the GI tract due to the inflamed colonic surface.

Figure 3

Figure 4

Figure 5

 Phenylbutazone toxicity can range from mild to severe. Mild cases are rather common and may present as only mild colic symptoms following administration of the drug. As such, careful observation should be made at all times when treating with these types of drugs and a reduction in dose and frequency of administration should be considered sooner than later! Horses suffering from colonic ulcers do NOT respond to gastric ulcer medication such as ranitidine and omeprazole. There is no specific medication for this condition. Treatment includes termination of phenylbutazone treatment, de-bulking the diet (more pellets and less hay), and time. Prognosis is guarded for advanced cases and good for mild cases.