Written By Dr. Kris Hiney

This month we will finish our discussion of common causes of colic in the equine, and what you might do to prevent them. Previously we discussed the importance of having a thorough emergency plan in place in order to make a potential colic less stressful for you. We followed that with a discussion of the most common management practices which will help minimize your horse’s risk of colic. These included quality and consistency of the diet, proper hydration and parasite control to name a few. This month we will focus on some of the less common reasons horses may colic. Although less common, they are no less important for the owner to be aware of these possibilities.

The sex of your horse may increase its likelihood of colic. Remember that colic just refers to general abdominal pain. Some mares experience discomfort relative to their estrous cycle. If your mare routinely shows mild colic at three week intervals, her ovaries may be the culprit. Normally cycling mares will ovulate every 21 to 23 days and this event can be associated with discomfort. Having a reproductive exam can also rule out if she has an ovarian dysfunction exacerbating her discomfort. If you choose to breed your mare, you must also be aware of the possibilities of colic associated with pregnancy. During gestation, the mare may experience colicky symptoms due to movement of the fetus. That does not mean that colic signs during gestation should be discounted. Follow your normal procedures of a thorough exam and consult with your veterinarian. Finally, mares are often crampy after foaling, as the uterus continues to contract in order to expel the placenta. Additionally there is a greater potential for twisted bowels post foaling due to the extra “room” in the abdominal tract. Typically these mares will experience very severe pain. As I have personally had to suffer the loss of a mare with a new foal at her side, realize that these are very real possibilities. Monitoring mares closely in the post foaling period may allow you to catch symptoms early and perhaps save her life. All in all, realize that there are risks one has to assume when choosing to breed horses.

The lifestyle of your horse may also cause it to colic. Some horses experience far more stress due to competition or travel than other horses. Some horses dislike horse shows or competitions so intensely that they work themselves into spasmodic colic. If this is true, you really need to closely examine why your horse is experiencing stress. Are you asking too much of them? Do you warm-up or ask the horse to perform at a different level than at which you train? Is the change in environment or the close proximity of other horses too much? Try to acclimate the horse gradually to stressful scenarios. Be reasonable in your expectations of your horse. Consider how nervous or anxious you may be at shows. Isn’t it likely that your horse may also experience anxiety (albeit for perhaps different reasons)? Ultimately, it may be possible that that type of career may not be a great fit for your horse. Consider a less stressful type of competition or even re-homing the horse where it may be more comfortable. After all, competitions and events serve as recreation for most horse owners. Is it really fun if your partner is miserable?

When traveling to events, also consider how long the horse is in the trailer. Hauling in a horse trailer for long periods of time is actually fairly tiring for the horse. Ideally you should let the horse rest every 5-6 hours. Coupling that with a change in a horse’s normal feeding schedule and reduced access to water, can set the horse up for colic. At rest stops, consider offering your horse flavored water to ensure he maintains his water intake. Begin to accustom him to the flavoring at home to ensure he actually likes it. This is especially critical in hot weather, when the temperature in the trailer can exceed the external temperature. Horses may lose a substantial amount of water through sweating that they may not have the opportunity to replenish. Horses may also be more likely to develop respiratory issues while confined in a trailer as well. While we often try to help the horse by keeping hay in front of them, open windows or sides can force dust and particulate matter into the horse’s airways. This can cause the horse to develop pleuritis, which is inflammation of the lungs. While it is a respiratory issue, the horse may still show colic-like symptoms. All in all, plan your travel with your horse’s comfort and health in mind.

What breed your horse is may also pre-dispose him to certain gastrointestinal disorders. Arabians and Arabian crosses are more likely to develop enteroliths than other breeds of horses. Enteroliths are essentially an accumulation of mineral within the intestine which forms a rock-like object. This can range in size from very small to the size of a softball or larger. While the reason is not yet known, this risk increases when these horses are fed alfalfa. This is especially true in the California and in other parts of the Southwest. However, this does not mean that a Quarter Horse in Iowa can’t develop an enterolith, they are just less likely to do so. High alfalfa diets are thought to cause enteroliths due to the high level of magnesium and protein combining to form crystals which make up the enteroliths. Diets higher in wheat bran have high levels of phosphorous which also contribute to enterolith formation. It is also possible that feeding highly digestible, lower fiber feeds like alfalfa may reduce gastric motility, allowing crystals to form more easily. Other lifestyle factors which lower gastric motility, such as lack of exercise or low frequency of feeding, increase the risk factor of enteroliths. Even the type of bedding chosen to be used can affect a horse’s risk of developing enteroliths. Horses on straw bedding, which allows an opportunity to nibble on high fiber feedstuffs, experience less enteroliths. While many believe that adding vinegar to the horse’s diet to lower colon pH may prevent enterolith formation, this has not been proven. Ideally, lower the amount of alfalfa in the horse’s diet, feed frequently and allow ample exercise are the best management choices.

While we can never completely ensure that our horses will never colic, following practical management strategies can lower these risks. Informed horse owners are those whose horses usually experience less health issues. Hopefully if you follow these tips from our last series you can have a colic free 2014! Until next month, enjoy some winter riding!