What is colic in horses?
Colic is defined as abdominal pain. It could be associated with any organ in the abdominal cavity. Generally, it refers to pain originating from the digestive tract. Colic is one of the most common causes of emergency treatment in horses. It also is the leading disease cause of death in horses.
What causes it?
Causes are many and are classified according to the contributory causes, disease present and the location in the gastrointestinal tract where the problem occurs. Examples include: ileus from intestinal spasms, gas colic resulting from nonstructural carbohydrates (starch and sugars) overloading the small intestine, obstructive colic which may be an impaction of the small or large intestine, enteritis or colitis which is inflammation of the small or large intestine, displacement, strangulation and gastric or intestinal ulcers.
What are contributory factors? (Excluding parasites)
- Starch overload. The feeding of cereal grains with high levels of starch that exceed the capacity of the small intestine’s ability to enzymatically break down starch and sugars, undigested starch and sugars that reach the cecum create acidosis which result in gas production, death of fibrolytic bacteria, rapid multiplication of pathogenic bacteria, destruction of the intestinal mucosa and the absorption of toxins. Gas production can contribute to displacement of the colon and strangulation. The amount of feed presented to the horse, the starch level in the feed, the source of the starch, the processing of the feed and the rate of intake are factors that can contribute. There are individual differences among horses but starch levels should not exceed 0.2% of body weight per meal.
- Impaction – This occurs within the lumen of intestine and may be associated with poor quality hay, lack of water consumption, large meal size, poor dental function and feeding high levels of starch. It is recommended not to exceed 0.5% of bodyweight per meal on the concentrate fed.
- Lack of forage – Forage should be available free choice preferably but should be fed at 1.5 – 2% of body weight per day.
- Pasture – Lack of access to pasture can be a contributory factor. Grass contains 70%+ moisture and the grazing process allows for exercise and trickle consumption.
- Change of diet – Changing hay or feed should be done gradually to allow the microflora to adapt. Sudden abrupt changes in feed or hay can be contributory factors.
- Feeding management practices – if possible feed individually. Competitive group feeding can cause horses to ingest too much and too rapidly. If horses are fed in groups use feeders that are spread out.
- Feeding routine should be consistent. Try and space the meals out and not feed meals close together.
- Feeding routine should have hay put out first before the feed. This will slow feed intake which is desirable.
- Avoid moldy feed and hay. Feed and hay should be stored properly and should be examined for the presence of mold.
- Inadequate water consumption is a contributory factor. Fresh clean water should be readily available at all times.
- Free choice salt preferably in loose form.
- Avoid alfalfa hay with blister beetles, black walnut shavings as bedding. Feeding management should address the prevention of sand ingestion where sandy soils occur.
Content provided by: Dr. Jim Ward, DVM, Equine Management Consultant, Cargill, Inc.
A few months ago, I received a call from a farm that was experiencing numerous cases of colic. They were concerned that their grain was the cause of the problem and asked me to visit their farm.
When I arrived at 8:30 am, the horses were just being fed. As I walked into the barn I noticed all of the stall fronts and side boards showed signs of chewing. I also noticed that many of the horses had little or no water in their buckets. Each horse received a large scoop of sweet feed and a flake of hay.
I reviewed the horses’ weight and body condition scores with the owner and trainer. Based on that assessment, I suggested they move to feeding hay at a rate of 1.5% of the horses’ body weight, and grain at the rate of 0.5 %. I also suggested going to a pelleted feed, as the horses were passing a lot of undigested grain in their manure. I encouraged the farm to select a pellet high in fiber and fat, and that contained yeast cultures to aid in the digestion process.
I then asked the farm owner to describe the daily routine at the farm. He explained once the horses are fed, they begin a daily work and turnout routine. At about noon, they are given another flake of hay or have round bales in their turnout area. By 3:30, all of the horses are brought in for their evening feeding. The evening feed consisted of a scoop of grain and two flakes of hay. The barn is closed for the day by 4:00 p.m. The horses were receiving all of their daily rations in 3 feedings, but they were within an 8 hour period.
By spanning the daily rations over a 14 hour period, ensuring full water buckets throughout the day, and following the product selection suggestions I had made, the farm has now been colic free for over 6 months!
Many horse owners are concerned about carbohydratelevels in their horses diet, particularly if the horse is prone to colic or laminitis. Often, the owner will look to simply feed a product with a lower starch or NSC percentage. But that’s often not the best, or only, solution, particularly if elevated levels of performance are expected of the horse, because the percent of starch in the feed isn’t what matters to a horse’s digestive system – what truly matters is the total amount of starch that enters the digestive system per meal.
When a horse consumes too much NSC in one meal, the starches and sugars may not be completely broken down and absorbed in the small intestine. Undigested starch getting to the hindgut may cause rapid fermentation by the microbes (gut bugs) that live in the cecum and large intestine, which results in gas production & lactic acid buildup. The gas buildup can result in colic, while the lactic acid accumulation drops the pH of the gut, starting a chain of events that may compromise the blood supply to the hoof, resulting in laminitis.
Here’s the catch: all horses need some NSC in the diet to live and work for you – it is a simple biological need. Hard working horses need higher, but still controlled, intakes of starches and sugars to provide readily available energy for work and to replace the glycogen (stored energy) that may have been used up during intense exercise. NSC intake is important for horses to recover from hard work.
If higher total intakes of starch and sugar are required to maintain energy levels, but the potential for digestive upset or laminitic episodes is a primary concern, the horse may benefit from more frequent but smaller meals during periods when extra calories are needed to recover from hard work. The higher daily intake, using more frequent feedings, will provide additional starch and sugar, as well as other nutrients your horse needs, while helping reduce the risk of digestive disturbances related to higher starch intake in a single meal.