A Long and Happy Life

PPE Gil Riley 13

Understanding the horse’s delicate digestive system can help to guard against colic and keep older horses healthy and happy 

by Petplan Equine Vet, Gil Riley

The old adage that prevention is better than cure is never truer than in the case of colic which is one of the most common causes of equine fatality, particularly in older horses. As with any condition, the key to prevention is understanding the causes and the steps that can be taken to avoid them.

Colic is a not an illness but a term used to describe the symptoms of abdominal pain, which in horses are usually caused by problems in the gastrointestinal tract. There are over 70 different types of intestinal problems that cause colic symptoms, which can range from mild to severe and life threatening.

Good digestion starts in the mouth

Maintaining a healthy digestive system is one of the most important factors in preventing colic. Well chewed food is the first step to good digestion so make sure that your horse’s teeth are in good condition. Ask a vet or equine dentist to check your horse’s teeth at least once and preferably twice a year. This is particularly important with older horses to ensure they are still able to chew their food effectively.

Feed little and often

When a horse swallows food it travels down the oesophagus (food pipe) into the stomach, which is about the same size as a rugby ball. Because horses have relatively small stomachs for their size they need to feed little and often.  The stomach is really an entrance portal to the intestine, which is a huge tube that acts like a conveyor belt and ‘stews’ food over a period of time.  Grass is a difficult product to break down and the longer the gut, the more likely that something can go wrong, so it is important to keep the horse’s diet as consistent as possible.

Introduce dietary changes gradually

From the intestine the food moves into the caecum, which is the size of a space hopper but the shape of a cigar. This is the fermentation vat in the horse and contains billions of microbes and flora to help break down the food. Sudden changes in the diet can confuse the microbes and lead to flora dying off and toxins being released, which can also result in laminitis.

Provide plenty of fresh water

The caecum leads into the colon, which is between four to eight metres in length and the width of a drainage pipe so a massive structure to be accommodated in the abdomen of the horse. The colon is where water is reabsorbed and nutrients are absorbed. Dehydration can lead to impaction colic so providing a good supply of clean, fresh water is vital. If your horse is bedded on straw make sure that you feed him regularly as if the horse eats straw bedding this can also lead to an impaction colic.

Tape worm and encysted redworm

Worms are a major enemy of a horse’s digestive system and regular worming is vital. The second most important parasite that horses are affected by is the tapeworm and this is found in the junction of the small intestine, caecum and colon. A blood test can measure the horse’s recent exposure to tapeworm and there are some effective products on the market to control it.

But by far the most important worm that affects horses is the small red worm, which inhabits the cecum and colon. It has a simple lifecycle, replicates very quickly and, through grazing, horses can easily re-infest themselves and infest other horses. The small red worm has levels of resistance to many worming products and can also burrow into the wall of the caecum and colon and encyst or ‘play dead’.  In this state it does not metabolise so survives any wormers and can then re-emerge into the caecum or colon after the wormer given has cleared the system. It tends to re-emerge in autumn/winter so it is important to worm horses at this time with a product that is effective against small red worm and has a duration activity so that it is still around to act on the encysted larvae as they emerge.

Age matters

As horses get older, their digestive systems can become less efficient and they tend to be more susceptible to colic so, if your horse is approaching the veteran stage, it is more important than ever to put preventative measures in place in your management programme. With colic claims regularly reaching in to the thousands it may be worth thinking about insurance to ensure you can afford veterinary treatment for your horse if, despite your best efforts, your horse still suffers a bout of colic.

Top Tips for Colic Prevention

1. Have your horse’s teeth checked regularly

2. Feed little and often

3. Keep the diet consistent and introduce any changes gradually

4. Administer a wormer that is effective against red worm, on November 5th

5. Always provide plenty of fresh, clean water

About Gil Riley

Gil Riley is a former Petplan Vet of the Year. A big thanks to Petplan for allowing us to share Gil’s article!