Colic is frightening and can be life-threatening. It is one of the major causes of death in horses and ponies, so it is understandable that it is something we want to avoid. There are many different types and causes of colic and not all can be prevented; however, there are ways to reduce the risk.
What is colic?
Colic just means signs of pain coming from the abdomen (belly). It can include pain from organs outside the gastrointestinal tract (for example, the bladder) but usually, when we talk about colic, we are talking about pain coming from the horse’s gastrointestinal tract which includes the stomach, small intestines and large intestines.
What causes it?
There are lots of causes of colic and lots of ways that the normal function of the gastrointestinal tract can be affected, which leads to pain. The intestines normally have a coordinated rhythmic pulse of contraction which moves food down the tract. This is called peristalsis. A common cause of colic is when this rhythm or pattern is altered, and although the intestines are working hard, they are not working correctly or in the right sequence, so food isn’t being moved down as it should. When this occurs the horse is in pain, and you can sometimes hear loud gut sounds even without a stethoscope – this is what we call spasmodic colic.
Another fairly common cause is food impaction, where a lump of food material (which can be anything, including hay, hard feed etc) stops moving along and starts to cause a partial or full blockage of the intestine. Other causes are a twist of the intestine, cutting off the blood supply, the intestines stopping working at all, or what is called an intussusception – which is when one part of the intestine actually goes inside the next part, a bit like a telescope sliding closed. There are many, many more causes.
What are the signs?
Colic signs are very varied and range from very subtle signs to very dramatic and dangerous behaviour. Horses can show some or all of the signs and it is important to look out for changes in behaviour including:
- Frequent yawning
- Frequent flehmen’s sign (curling the upper lip)
- Looking round at their belly
- Pawing the ground
- Not eating
- Stretching out as if to urinate
- Lifting hind legs
- Flapping their tail
- Kicking at their belly
- Lying down and getting up
- Lying flat out
- Rolling
Reducing the risk
How can we reduce the risk of colic? We will look at several factors that can be managed to reduce the risk of colic. Unfortunately, we cannot remove the risk entirely.
Feeding is a big overall factor. To reduce the risk of colic your horse should eat a fibre-based diet with 2% of their bodyweight in forage (and this is weight on a dry matter basis which means the pure weight of the plant with the water removed). So, a 500kg horse should eat 10kg DM hay (which is about 11kg of hay) per day. Horses naturally graze for 16-20 hours per 24 hours and their gut copes best when they have an almost continuous supply of food rather than a large amount intermittently. Mimicking this natural behaviour will help reduce the risk of colic. We are very lucky in New Zealand as the majority of our horses and ponies are pasture based. However, there are times when horses are off pasture, and it is then that it is important to keep a regular food supply.
Make any changes to feed gradually. This is very important as in the horse’s gastrointestinal tract are millions of tiny living things called microbes. These include lots of different types of bacteria and protozoa. This population is affected by the horse’s diet as different species flourish with different diets, one type increases and another decreases as the diet changes. These changes take time and if a change is made too suddenly the microbes won’t be able to cope and this can lead to colic. Make any changes gradually and introduce new food slowly, whether this is a new batch of hay mixing it in with your old one or adding in a completely new feed a small amount at a time.
Maximise time at pasture. As has been discussed we are very fortunate with our horses and ponies at grass for most of the time and this is important to continue to reduce the risk of colic both by continuous ability to feed and also by allowing movement and exercise. Research has shown that stabled or stalled horses have reduced large intestinal movement, and this is a risk factor for colic. Movement is very important to keep the guts working well.
Have clean fresh water always available – this should be easy! But it also has to be water they will drink, and some horses can be surprisingly picky about the water they will drink from a bucket (even if they will drink from any random muddy puddle). They get used to the taste of home water and can refuse to drink any different tasting water for days. If you’re travelling with your horse, you need to consider this. If you’re only away for a short time, you may be able to take enough home water with you. For longer trips, this won’t be practical, so a suggestion is to get your horse used to drinking flavoured water at home well before you leave, so they won’t notice the difference. Options include a small amount of molasses, apple juice or apple sauce, or mint. Keeping trying until you find the right flavour for your horse.
More risk factors
Poor dental health: A horse uses a figure-of-eight motion to grind food, so the jaws move side to side as well as up and down. If there are any dental abnormalities to prevent this motion (sharp points or hooks etc.) then food won’t be ground down as it should be. Swallowing long stalky fibres may increase the risk of impaction, and undigested feed may also lead to colic, so keeping your horse’s teeth in great condition, enabling them to work properly, will help reduce the risk of colic. Have your horse’s teeth examined by a vet or equine dentist at least once a year.
A worm burden: Internal parasites can cause inflammation, damage and changes in the motility of the intestines, all of which can cause colic. Developing a worming programme with your veterinarian for your horse in your specific grazing and management situation will help reduce the risk of colic.
Stress: What causes stress will vary from horse to horse and pony to pony. We cannot avoid stress completely, but we should try and plan things as much as possible to avoid sudden dramatic changes to a routine and to introduce changes gradually. Some horses are much more affected by changes to their general management and exercise routine (not just feed) than others. You will need to work out what is best for your horse. Vets see a number of cases of colic at big shows and other events when there has been a big change in the routine. Plan to keep as much as normal as possible, and try building up to big events to help reduce the effects of these changes.
Know your horse
This is not so much about reducing risk but about noticing a problem sooner. Many times, early treatment will lead to a higher chance of a successful outcome from colic. But to notice when something is wrong, you need to know what is normal first.
Watching your horses or pony for a few minutes before they see you and respond to you is really worthwhile – you can learn a lot.
In addition, learning how to take your horse’s pulse rate, respiration rate and getting them used to you looking at the colour of their gums will all be useful if you are worried that they are sick.
Take note of your horse’s manure. It sounds a bit strange but it can give you a hint as to what is going on inside!
Summary
Reduce risk – keep to a high fibre/ lower grain diet, make any changes in any type of feed gradually, ensure they have access to water and are drinking it, allow as much turn out as possible, try to keep to a good routine, reduce stress as much as possible, develop a good worming programme for your situation, keep up with regular dental care and get to know your horse’s normals. Plan carefully for trips to shows, events, treks or holidays to avoid sudden changes where possible.
As always, don’t hesitate to call your veterinarian if you are concerned about anything with your horse. If you notice any of the signs or any changes from their normal behaviour, get in touch with your vet. Colic is one of many conditions where early treatment gives a better chance of a successful outcome.
There is a Canadian online tool to calculate your horse’s risk of colic which is interesting to go through and then think about ways to reduce the risk. Check it out at thehorseportal.ca/healthcare-tools/colic-tool/
