Tuesday, 17 August 2010 11:09

“Doc – Colic in my horses scares me to death! I'd like to know more about it!”

Written by  A.J. Neumann, D.V.M.
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Part I

The word “colic” comes from the Greek work “k_likos” which meant, “relating to the colon” or its English use is “spasmodic pains in the abdomen.” When a horse or mule is diagnosed as “having a colic” this in itself means the animal is having abdominal pain. Mention the word “colic” to a group of horse owners and some will almost certainly conjure up the picture of one of their horses rolling about, kicking, sweating and finally dying after suffering terrific abdominal pain. No wonder the word “colic” inspires some degree of fear in a horseman or woman.

If an animal is diagnosed with “the colic” this merely means that it is exhibiting signs or symptoms of abdominal pain. These symptoms vary in severity due to the type or cause of the colic. What are some of the symptoms seen in the affected animal?

In the most mild cases the owners are often baffled as to what is really happening. The animal will just stand or lie down on its sternum and turn its head to look at its flank, mainly looking only at the left side. It may get up and walk around with the head down and then lie down again. They usually refuse to eat and sometimes will go to a water source and “play” in it with their lips.

As the severity of the case increases so the evidence of pain increases in the patient. The animal will begin to sweat. Its breathing will become more and more labored. It will go down and roll from side to side, often kicking and striking as it rolls. It will get up and immediately go down again, until it is almost impossible to keep it on its feet. Of course there are also changes taking place with the heart rate, body temperature, gut sounds, capillary fill time, abdominal sensitivity, respiratory rate and blood chemistry. I have found a very telling symptom of the severity of the colic can be read in the patient’s eye. I have noted that a close study of the eyes of “colicky” horses will reveal much about the severity, the cause and often the outcome of the case. Anyway, these are the symptoms anyone can see, feel and hear when observing colic in the equine.

The type or kind of colic depends generally on the cause. Here is a classification of colic as I was taught in college. They are also listed in order of their occurrence: Verminous colic; Spasmodic colic; Flatulent and stomach dilation or gas colic; Colic due to Gastric Duodenal Ulcers and Enteritis; Intestinal obstruction due to malposition; Impaction colic; Colic due to pregnancy in the mare and last of all Azoturia of the intestinal tract. A colic in a horse, mule or ass will fall into one of these categories.

Verminous Colic

It has been known for many years that an infection with Strongylus vulgaris would cause colic. The infection was once reported to cause 90% of all colic in horses. With the advent of the newer anthelmintics, especially ivermectin, colic due to this strongyle has declined rapidly. Small strongyli, ascarids, tapeworms and bot larvae are also incriminated in causing colic in heavily infected animals, especially in foals and weanlings.

This type of colic can be entirely prevented by the implementation of a rigorous worming schedule using several of the new anthelmintics. Not only will their use prevent this form of colic but the treated animals free of parasites, will grow and develop wonderfully well on much less feed. After all, if the parasites are not there you are not feeding them!

An interesting fact was told to me by an insurance representative about 3 years after the introduction of ivermectin. He said claims for equine deaths due to endoparasitism were down about 90%.

Spasmodic Colic

Spasmodic colic is a very common form of colic in the equine. This form of colic is relatively easy to diagnose by either the owner or a veterinarian. The history of the feeding, watering and working schedules of the affected animal is very important when diagnosing this colic condition. Horses especially are very vulnerable to changes in their regular routine and these changes will produce this form of colic. Too much cold water, irregular feeding patterns, abrupt changes in feed, feeding hay that is not cured, grain fed that is warm or hot, horse transport and even vaccination are some of the most common factors that will produce the so called spasmodic colic in the animal.

It has been found that any change in a horse’s daily routine will put the animal at risk for this form of colic. A nervous horse is much more susceptible than others. Weather conditions, especially times of low humidity, have been found to precede, in some horses, this spasmodic colic type.

A good equine practitioner should have very little problem in diagnosing and treating this form of colic.

Flatulent or Gas Colic and Stomach Dilation

In discussing this form of colic of the equine I am referring to gas, which is produced in the stomach or intestinal tract due primarily to feed or feeding practices, not due to intestinal obstructions or malpositions of the intestinal tract.

Yes, horses can bloat as well as cattle or sheep. Most every stockman is well aware of the problem in sheep and cattle but never thinks it can occur in the mule or horse. Yet it is more common than one would suppose, especially involving the cecum and the stomach as well as the large intestine.

The most common cause of stomach or gastric and cecal dilation or bloat is overeating on certain feeds. Fresh green alfalfa or red clover, especially when the forage is wet, will cause a horse to bloat just as it will cattle or sheep. Cereal grains such as oats, wheat, barley and rye especially if they are ground will cause bloating and will become packed into a doughy expanding mass in the stomach. The resulting dilation of the stomach is probably the most acute colic which can occur in the horse. The degree of pain exhibited by the animal is in direct correlation to the amount of dilation of the stomach.

There are several other contributing factors to this form of colic. Horses that have been deprived of water for a period of time and allowed to eat grain before drinking are at a great risk of developing this form of colic. Bot larvae may cause the stomach’s exit, called the pylorus to be closed, resulting in the distention of the stomach. Another common cause of stomach dilation is “cribbing.” This, of course, is a vice and the “cribber” will often fill the stomach with gas and when food or water is taken in, the colic begins.

When the stomach is dilated in most species of animals, they will vomit. In the horse and mule, vomiting is very difficult and should it occur, large amounts of ingested feed and fluid are expelled with great force usually going through the nasal passages and out the nose. If this happens there is a very good chance that some of the expelled ingesta will be inhaled and the animal will suffer from inhalation pneumonia.

In this form of colic the abdominal pain is very severe. The animal will sweat, kick, strike, roll and in an attempt to relieve the pain it will sit on its rear quarters much like a dog. The bloated horse will be like a big drum and it will not lie down because the resulting pressure will keep it from breathing and it will die.

Decompression of the stomach can only be done with a nasal gastric tube often referred to as an equine stomach tube. The cecum and large intestine can be relieved of gas, or decompressed, by the use of a horse trochar, or, in its absence, a 5 to 6-inch 14 or 16-gauge needle.

Colic Due to Gastroduodenal Ulcers and Enteritis

Gastric or stomach ulcers can be found in a large number of foals, yearlings and adult horses. Duodenal ulcers, those found in the first few feet of the small intestine, occur primarily in foals although the condition has been found in yearlings. This type of ulceration is very rare in the adult horse.

Enteritis, or an inflammation of the gut wall, is common to all ages of horses and mules. Enteritis has many causes. One sees enteritis and diarrhea in Salmonellosis, Potomac Horse Fever, Clostridial and E. Coli infections. Antibiotics administered orally or parenterally can sometimes cause an acute diarrhea. Some of the known antibiotics which may cause a diarrhea are erythromycin, penicillin, lincomycin, tetracycline, metronidazole, and trimethoprim/sulfa.

Horses and mules showing evidence of diarrhea or those suspected of having gastric or duodenal ulcers may show the signs of colic. This is especially true with foals. When treating a colic involving a foal, especially those younger than 1 month, there are a goodly number of causes for the condition, but do not overlook a very common one and that is the presence of these ulcers which often can cause the problem.

Intestinal Obstruction Due to Malposition of a Segment

To use a layman’s term, this condition is often referred to as a “twisted gut.” Generally, there are three medical terms used to describe this condition. They are: Torsion, Voloulus and Intussusception. In torsion, a piece of the intestine is twisted on itself. Voloulus is the term used when a segment of intestine knots or twists on itself much the same as seen in torsion. Intussusception occurs when a portion of the intestinal tract telescopes into an adjacent portion. The latter, intussusception, is primarily seen in foals, although it can occur in other aged horses, although rarely.

Probably the most frequent cause of voloulus is indigestion with its associated pain, which, in turn, causes the horse to move suddenly and roll violently.

The ileum, a section of the small intestine, is often involved because of the long mesentery which holds it in place and contains the vital blood and nerve supply to it.

There are also other factors which can cause this obstruction or strangulation of an intestinal segment. Two very common causes are umbilical and scrotal hernias. These are especially important in the newborn foal. Should they occur in the newborn they should be dealt with immediately so as to prevent strangulation of a portion of the intestine, which may become trapped in the hernia.

Occasionally, a stallion that has just bred a mare, will come down with an acute colic. The affected animal should always be checked rectally as a number of these cases will have a segment of intestine which has passed through the inguinal ring and has become strangulated.

This form of colic will appear suddenly and there usually is intense and continuous pain. It is imperative that a proper diagnosis be made as soon as possible since surgical intervention is usually the only resort for the animal’s recovery. It is very important that the equine practitioner attending these colic cases perform a thorough physical examination of the patient before reaching a positive diagnosis of the condition.

Impaction Colic

Impaction refers to an accumulation of food which becomes stuck in some area of the intestinal tract. The blockage may be complete or partial. In the draft horse, impactions of the colon and cecum are the most common areas involved.

In the Midwest, impactions are quite frequent occurring usually from October through March. Predisposing factors are: 1-changes from warm to very cold weather; 2-changes from green forage to dry; 3-damaged or moldy forage; 4-in using a draft horse–too much work resulting in fatigue; 5-not enough available water (I think this one is very important as a number of people believe a horse does not need a source of water if there are snow banks and snow drifts available); 6-old and thin horses; 7-severe parasitism; 8-tumors; 9-dental defects.

Any of these factors can be involved in intestinal impactions. However, most are caused by feeding a low quality forage high in fiber along with a reduced water intake. (The snowdrift!!)

Impactions of the small intestine usually cause severe and continuous pain while those occurring in the cecum, large intestine and rectum are less painful. In the latter, the colic is often intermittent.

As a general rule, impactions of the intestinal tract are relatively easy to diagnose and most can be successfully treated without surgery.

Colic Due to Pregnancy In The Mare

Pregnant mares have an increased risk of colic before and after delivering the foal. In fact, it was shown in a Virginia-Maryland study that mares have an increased risk from 60 to 150 days after foaling.

The colics associated with pregnancy, which occur before delivery are thought to be caused by the movements of the foal in the uterus. Almost every owner of a pregnant mare has seen the foal violently move especially if the mare drinks very cold water. These mares seem to have a higher risk for colon displacement and that could be attributed to the movement of the foal in the uterus.

After foaling, the predisposing factors are not known but diet and calcium levels may have a part in the program. In many cases of mare eclampsia or milk fever, a colic is often observed and the administration of calcium I.V. will solve the problem.

Azoturia of The Intestinal Tract

Okay; I know I am using an old term, and that dates me! Azoturia has been dropped from professional use and combined under the heading of Rhabdomyolysis. The ordinary person can not even pronounce the term, let alone understand all there is known about the condition.

When I went to college I was taught this little classification of colic by “draft horse” instructors. I have seen the condition often and treated every one of the cases successfully. When I attend draft horse shows I always carry the meds with me to treat it as often someone showing their stock will have a case.

The scenario goes like this. The draft animal is shown in one or more hitch classes. Naturally the animal is in perfect physical condition but probably a bit overweight and used to a diet high in grain or some form of enriched feed. When the show is over the animal is stabled and, low and behold, in about 30 to 60 minutes it is colicky.

On the outside the horse appears normal but its whole digestive tract and urinary apparatus has shut down.

The treatment is by the I.V. route and these cases will fully recover in less than an hour.

I do not know if light horses at the show have the same problem but I am well aware that the draft horse at the show is susceptible to this form of colic. I remember very distinctly treating three horses at the National Western Stock Show in Denver, Colorado, for this form of colic in one year.

In the next issue of The Draft Horse Journal I will walk the readers through some very important measures they should be taking to prevent these colics in their herds.

I will tell you some of the procedures a veterinarian should do when he or she attempts to diagnose a case of colic. You, the owner of the horse, should know what to expect from the veterinarian.

I also will discuss some procedures that should always be undertaken if a case of colic is to be treated medically.

And then there’s this: One time I was visiting with an elderly gentleman, a draft horse owner, and the subject got around to treating colics. He informed me his treatment had never failed to cure the horse with colic. I asked what he did. He replied, “If I have a horse with colic I paint the navel area with turpentine. It always cures them.”

You can try it–I have! Let me know how it works

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