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!
Water is the most important nutrient that we provide for horses on a year around basis. Horses need 2 to 3 times more water than other feedstuffs. An 1100 lb horse on a dry forage diet at an average temperature of 68 degrees Fahrenheit will need a minimum of 6-7 gallons of water per day or 48-56 lbs of water, and many horses will drink more water than the minimum. We all appreciate that the water requirement may double at high temperatures, but may not realize that at -4 degrees Fahrenheit; the quantity required is about 10-12 gallons per day, or actually higher than at moderate temperature. The onset of cold weather can actually increase the requirement for water because there is no fresh grass and the air is very dry.
There is a misconception that domestic horses can easily eat enough snow to survive. While horses in the wild do adapt to lower water intakes, partially because food intake is also frequently reduced, horses can survive longer without food than they can without water. Reduced water intake can also impair digestion and potentially contribute to the incidence of impaction colic.
It also requires a great deal of energy to eat snow, melt the snow in the body and raise the fluid temperature to normal body temperature of 99.5- 100.5. Increasing the temperature of 10 gallons of water from 32 degrees to 100 degrees takes about 1372 Calories or about the amount of digestible energy in a pound of feed. Melting the snow to get to water will take a great deal more energy and the horses will not readily eat a pile of snow the size of 20 five gallon buckets. It takes about 10 inches of snow to have one inch of water.
Providing horses with fresh clean water at an appropriate temperature all year around is a great management tool to reduce the risk of colic, maintain healthy digestion, maintain body condition and even save a bit of money on feed cost!