Preventing Impaction Colic Recurrence

An equine nutritionist offers feeding advice to minimize the risk of impaction colic in senior horses.

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Preventing Impaction Colic Recurrence
Common causes of impactions include dehydration and poorly digested feed. Ensure your horse is consuming enough water every day to avoid dehydration.| Photo: Thinkstock

Q: I have a 28-year-old gelding who suffered an impaction colic last week. We’re not really sure why it happened, because nothing has changed in how he is managed. What can I do to help prevent it from happening again?

A: Colic is scary to witness, and not knowing the cause can be very stressful. Of course we all want to make sure it doesn’t happen again. Assuming there’s no physical cause for impaction, such as a tumor, which can occur in older horses, common causes include dehydration and poorly digested feed. Therefore, avoiding dehydration and improving digestion are key.

Salt and Hydration

Ensuring your horse is consuming enough water is necessary for avoiding dehydration. Sodium intake each day helps stimulate water consumption, so make sure your horse gets enough salt each day. Many owners rely on salt blocks to provide their horses with a sodium source, but few horses adequately utilize salt blocks.

An average 1,100-pound horse must consume about an ounce of sodium chloride a day to meet maintenance sodium requirements. This would be equivalent to consuming 2 pounds of salt in block form each month. Few horses achieve this intake from blocks. Therefore, I like to feed horses an ounce of salt (which is 2 tablespoons) each day and then provide them access to a plain white salt block, as well. If the weather is hotter, then you can give additional salt or an electrolyte supplement. If your horse does not like the taste of salt, then you can use an electrolyte instead, because sometimes electrolytes are more palatable than straight salt.

Salt consumption should stimulate thirst and encourage your horse to drink. Make sure water is easily accessible. If older horses have joint pain they might be less willing to walk distances to get to water, so consider having several water sources available. When feeding hay, you might find your horse drinks more if water is near his hay.

Soaking Hay

That said, soaking hay is an effective management strategy for horses prone to impaction colic. First, it increases water intake without the need for drinking more water, and secondly it softens the hay and makes it easier to chew. Keep in mind that horses fed soaked hay might not consume as much water from other sources, such as buckets or troughs, so it might initially appear that your horse is consuming less water.

Even if senior horses have healthy teeth, they might not have as much strength in their jaws to grind and chew hay as when they were younger. Inadequately chewed hay creates a greater impaction risk. Soaking hay to make it softer can be beneficial. Feeding softer, less stemmy hays might also help, because they tend to be more easily digestible. Senior horses that can graze pasture grass safely might have a reduced impaction risk when grazing, because fresh grass contains more water and is softer and easier to chew than hay.

Pellets Instead of Hay

For some horses, feeding hay pellets might be a better option than long-stem hay. Once chewed, pellets have very small particle sizes, which reduces impaction colic risk. If desired, you can feed pellets soaked. In fact, you can prepare any textured or pelleted feed as a mash or soup as a way of increasing water consumption.

Hindgut Health

Special Feature | Dealing With Equine Colic: Here are 33 Do's and Don'ts
Special Feature | Dealing With Equine Colic: Here are 33 Do’s and Don’ts

In addition to making sure your horse consumes enough water and chews his forage properly, supporting forage digestion might be beneficial. Research shows supplemental live yeast can help improve organic matter utilization in the hindgut. This improvement in forage fermentation might help reduce the risk of hindgut impaction.


Finally, make sure your horse is getting adequate exercise, as movement aids digestion. Senior horses tend to move less due to joint pain or because they have been retired from riding. Have your veterinarian look over your horse and provide him with support for any joint discomfort. If your horse isn’t turned out, consider at least hand-walking or longing him each day.

Take-Home Message

By implementing some of these recommendations and practicing overall careful management you can potentially limit your older horse’s risk of a repeat impaction colic episode.


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Written by:

Clair Thunes, PhD, is an equine nutritionist who owns Clarity Equine Nutrition, based in Gilbert, Arizona. She works as a consultant with owners/trainers and veterinarians across the United States and globally to take the guesswork out of feeding horses and provides services to select companies. As a nutritionist she works with all equids, from WEG competitors to Miniature donkeys and everything in between. Born in England, she earned her undergraduate degree at Edinburgh University, in Scotland, and her master’s and doctorate in nutrition at the University of California, Davis. Growing up, she competed in a wide array of disciplines and was an active member of the U.K. Pony Club. Today, she serves as the district commissioner for the Salt River Pony Club.

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