Is sweet itch affecting fewer horses than we think?

When horses exhibit summertime rubbing behaviour, sweet itch is often assumed to be the culprit. But there are many other potential causes of summertime rubbing behaviour. As a consequence, many horses are treated for sweet itch without any results. This is why it is very important to determine the cause of rubbing behaviour in the summertime. Laminitis, sugars in their food, insect bite sensitivity, obesity and other types of itches are all potential causes of a summertime itch. Some horses rub as a result of fertilizer-treated fields. In short, summertime rubbing isn’t necessarily being caused by sweet itch. Below an overview of potential summertime itch causes and the associated measures you can take.

Rubbing due to obesity

Most horses in the Netherlands pack quite a bit of meat on the bone. We all know obesity is unhealthy for horses, as it is for humans. But did you know that obesity in horses can cause itchiness? Accumulations of fat spawn all kinds of minor inflammations underneath the skin, especially around the manes. These inflammations cause irritation which prompts the horse to start rubbing. The rubbing results in minor sores, which in turn cause inflammatory responses in that location. This cycle will not stop until something is done to stop it.

One of many reasons to have an obese horse lose weight is that the itch might be gone once the horse has reached a healthy weight. Make sure that your horse loses its weight gradually. Doing it too quickly will cause an excess of waste substances to be released into the body all at once, which may cause problems of its own.

Limit the intake of (rich) grass and rich roughage and opt for low-quality hay or bolted grass instead, which packs a lot of fibres. Strip grazing is also highly recommended. If possible, increase the training duration and frequency. When in doubt, consult your vet to find the best approach.

Always make sure your horse gets enough roughage throughout the day and maintain the recommended daily amounts of vitamins and minerals, for example by using a balancer. This is a basic necessity that each horse needs to stay healthy.

While your horse remains overweight, reduce its summertime itch with a sweet itch rug and a supplement to make the horse less appealing to insects. It is also recommended to treat any inflammations with a softening and therapeutic cream. This is how you break the cycle, prevent new inflammations and the associated itching.

Rubbing due to food and/or insulin resistance

Sugar is one of the major causes of itching, which usually emerges once the horses head back into the field in summertime. By grazing, the horses ingest large amounts of sugar which can cause itching and irritation in horses that are sensitive to sugars. In addition, sugars can trigger conditions such as Insulin Resistance, which exacerbates the risk of laminitis. Did you know that Insulin Resistance is associated with the same symptoms as sweet itch? These horses also tend to rub their makes, especially in summertime. Large amounts of dietary sugar can disrupt the intestinal flora. This disruption causes a disbalance in the body which compromises the immune system. As a result of a compromised immune system, minor inflammatory reactions appear which cause irritation.

A horse may also have an allergic response to certain food. It is important to find out what the horse is allergic to, in order to remove the allergen from its diet.

If your horse is sensitive to sugars/grass, limit its time in the field and keep a close eye on the fructan index to find out what time of day is safest for your horse to be out in the field. Make sure to feed it low-sugar roughage and concentrate (starch and carbohydrates). Be careful with sugar-rich treats!

Rubbing due to insect bites/parasites

Unfortunately, we are all too familiar with the culicoides midge (also known as gnats). These awful little mosquitoes tend to surround horses in large numbers, bringing them discomfort and terrible itches. Culicoides midges (gnats) cause sweet itch and make these horses rub their manes and tail root to smithereens if nothing is done about it.

The saliva of these mosquitoes is what causes the allergic response. Every bite leaves behind a little bit of the mosquito’s saliva, triggering the allergic response. An allergic response is an inflammatory reaction of the body, associated with itching and irritation that causes the horse to exhibit rubbing behaviour. It is important to cover these horses with a sweet itch blanket, detox them prior to the gnat season, give them a supplement to reduce their appeal to gnats, add cannabinoids to their food and, when there are lots of gnats, bring them back inside in time to treat any sores and prevent them from being rubbed open again.

In addition to culicoides midges (gnats), summertime itches can also be caused by lice, mites, fungi and worms. Always take the appropriate measures to stop the itch. Read here more about the treatment  of sweet itch in horses.

Other causes

An itch can have various potential causes. The main culprits are food, insulin resistance, insects and obesity. But an accumulation of waste substances in the body can also cause irritation which may prompt the horse to start rubbing. Give your horse a detox twice a year (spring and fall) to cleanse the body. It will help the horse absorb nutrients which will contribute to the horse’s immune system. Some horses are allergic to fertiliser. For example, not all horses can handle grassland treated with chemical fertiliser and it will cause them to start rubbing.

Conclusion:

A lot of horses are incorrectly labelled as ‘sweet itcher’ in summertime. Summertime itching and irritation isn’t always caused by sweet itch (culicoides midges (gnats)). Other major causes of severe itching are reactions to food and obesity. This is why it is important to find out the cause of your horse’s itch. Once that cause has been determined, you can take the appropriate action to get your horse through the summer as comfortably as possible!