Insulin resistance in your horse

Just as in people, overweight in horses is not healthy. A growing number of horses in the Europe are too fat and this increases the risk for conditions such as insulin resistance. What is insulin resistance, how does it occur and how can you help a horse with insulin resistance in the best possible way?

What is insulin?

Through its feed, a horse takes in various nutrients, including sugar and starch. These are not only found in concentrated feed, but also in grass, silage and hay. In the horse’s digestive tract, these nutrients are converted to glucose which is absorbed into the blood. Subsequently, the body should receive a signal that the glucose should be stored for example in muscle cells that use it as fuel. This signal is given by the hormone insulin that is produced in the pancreas. The higher the glucose level in the blood, the more insulin is being produced.

Insulin resistance in horses: too much sugar and too much insulin

This signalling process, however, can get terribly out of hand if the quantity of glucose entering the body remains high all the time which will result in an overload of the metabolism. If insulin is being produced for a longer period of time, the body’s sensitivity for it decreases. Subsequently, the pancreas will produce increasingly more insulin to make the body respond to the insulin. Finally, even an extremely high insulin production will not lower the glucose level sufficiently. This means that the glucose level in the blood will remain too high. The horse’s body is unable to cope with this and diabetes is the result. So it is vital that a horse suffering from insulin resistance should always get a feed with the lowest possible sugar content.

Horse with insulin resistance: the symptoms 

Insulin resistance in horses causes numerous problems. One of the worst conditions that can occur is laminitis. In order to find out whether your horse suffers from insulin resistance, you can ask your veterinary surgeon to perform a blood test. The reason is that it is very hard to observe from the outside.

Is insulin resistance typical for specific breeds?

It is a well-known fact that horses that take in more energy than they use will get fat. However, not all fat or obese horses appear to be suffering from insulin resistance. A clear correlation with certain breeds shows, though. Particularly ponies such as the Welsh pony, Wels Cob, Icelandic horses and Shetland ponies seem to be very sensitive to it. Genetics plays a role too. A clear relation between eating too much nutritive saccharides and laminitis does exist. So testing is important. Decrease the intake of sugar and make sure that your horse loses weight, and the sensitivity for insulin will decrease too.

Insulin resistance and grass

Do you want to prevent or fight insulin resistance? Then make sure your horse does not take in too much sugar and does not become too fat. When looking at its diet, it is not enough to just check on the concentrate feed. Grass for that matter is a huge source of sugars. Having access to grass is of course wonderful for a horse, but many mistakes are made when providing this access. People often think paddocks with little or no grass are best, but that is not the case. Short grass is ‘stressed’ grass that wants to grow fast. In order to grow fast, extra fructan is being produced, a type of sugar that horses are sensitive to. Cold spring and autumn nights provide an extra risk. Because of the cold, the metabolism of the plants stops as a result of which during the night the development of fructan does not decrease and in the course of the day, when it is very sunny, the metabolism starts up with an extra high sugar production. A tip: turn out horses with insulin resistance later on in the day (late afternoon or early evening) for a few hours, or perhaps do not turn them out at all.

Roughage such as hay and haylage contain sugar

But how much? You cannot tell from the outside. So it cannot be said that moist silage or rough hay is better for a horse. You only know for sure when you have had the roughage tested. Never provide the horse with less roughage as a preventative action; a horse needs a certain amount of roughage. In the wild, a horse will munch all day long, this is how its body evolved.

Horse feed without sugar

It is best to give a horse with insulin resistance feed with the lowest possible levels of sugar, starch or molasses. Restrict the amount of concentrates as much as possible and give, if possible, only a complete vitamin and mineral supplement, such as Pavo Vital or Pavo SummerFit biscuits. You can also opt for Pavo SpeediBeet as a low sugar content addition. Beet pulp is an individual raw material full of healthy fibres and a sugar content of only 4%. Pavo SpeediBeet does not contain starch at all. If you do need to provide your horse with concentrated feed, because your horse needs the extra energy, then it is best to give a feed with a low sugar and starch content, such as Pavo Nature’s Best and make sure to provide the feed in various portions per day. Mix the concentrated feed with roughage to prolong the chewing time. Pavo Care4Life is a special fibre-rich blend without wheat and with a high content of vitamins, minerals and herbs. It is very suitable for horses prone to insulin resistance.

Horse suffering from insulin resistance? This is what you can additionally do:

Insulin resistance in your horse can be combatted with sufficient movement (endurance training) in the form of walking, trotting and possibly cantering. Build this up properly, so that your horse gradually gets used to covering longer distances. Short, explosive exercises are not the proper training for fat or obese horses. Especially during endurance training the horse burns the most fat.

In addition, free movement in a paddock is very important, however in a paddock with little grass. Opt for example for strip grazing, or put your horse in a sand paddock with hay for a part of the day. Using a grazing muzzle is yet another option.