Allergies affect animals as much as humans – horses unfortunately are no different. Some are particularly allergic to the saliva in the bite from a Culicoides fly causing a condition known as Sweet Itch. This means that once a sensitive horse has been bitten by this particular midge, it will have an allergic reaction at the site of the bite. This will cause a localised irritation which the horse will scratch in an attempt to alleviate the itching. This however causes a never-ending cycle - by scratching himself, the horse only self-inflicts further damage. Sweet Itch can affect any horse or pony, although as a guideline symptoms normally begin to show between the ages of 1 and 5.
The culprit: the Culicoides fly
There are many different species of Culicoides midge, and each one prefers to bite a different part of the horse. The horse will then scratch the area around where the fly has bitten. Most common are the “dorsal feeders” that bite, and cause damage around the horse’s ears, poll, mane, withers, rump, and tail head. However in more severe cases they can also be affected by “ventral feeders”, which are generally less common. They tend to cause itching around the horse’s face, chest, and belly.
Due to the life cycle of these specific flies this is a seasonal disorder, as indicated above, characterized by severe itching. The horse in question may become restless, rubbing himself against trees or fences, and will keep swishing his tail in an attempt to ward off the flies. Other symptoms include hair loss as a result of rubbing against objects, flaky dandruff, skin thickening, weeping sores or dried yellow crusts. Early on in the disease, the skin will be bald, red, inflamed, crusting and sore. As the disease progresses, the skin becomes chronically thickened, blackened, and wrinkled and the hair becomes sparse and coarse. The tail becomes thinned and hard taking on an almost rat-tailed appearance. Over the winter, a horse may recover completely, only to find himself at square one when spring hits and he comes into contact with the flies yet again.
Regrettably, once a horse develops an allergic reaction to the Culicoides fly bite, there is no cure. Sweet Itch will occur every year so the comfort and wellbeing of the horse lies in the hands of the owner and how he/she manages the condition.
A lot can be done however to help minimize damage caused these midge bites:
- Avoiding marshy or swampy fields and ponds.
- Don't put the horse in a field or stable near rotting vegetation such as a muck heap or old hay feeding areas.
- Don't leave the horse in the field during peak feeding time for midges (1 hour before and after sunrise and sunset) – during this time stable the horse closing all doors and windows or use fine mesh screens. (It is important to note however that stabling horses is only prudent in mild/moderate cases as horses with more severe sweet itch can self damage on stable walls. Horses with severe Sweet Itch should not be stabled and other management methods need to be carried out).
- Insect-proof stables by using fine-mesh screens.
- Stable at night might help.
- Use commercially available sheets and hoods when horse is turned out.
- Clean water troughs regularly to prevent flies breeding in this area.
Treatment usually targets killing the flies and reducing the severe itchiness. Insecticides are generally used to kill and ward off the flies - specifically those that contain pyrethrins or pyrethroids as they last longer. For treating the skin allergy corticosteroids are commonly used and can only be prescribed by a vet as they are potent anti-inflammatories which target the itching allowing the skin time to heal. However, these do come with side effects and as with usage of all corticosteroids there is an increased risk of inducing laminitis in the horse. Anti-histamines have proven to be not as effective as they are for us humans and are known to be very pricey.
Natural itch fighter!
Natural remedies have proven to be very effective in treating angry, irritated skin. Herbs and homeopathic ingredients have shown to have many beneficial properties in treating itchiness in horses while supporting the health of the skin without the risk of side-effects. Homeopathic ingredients can help to address the intense itching associated with Sweet Itch. Arum triph has been used for centuries to support the skin and address the burning sensation on the skin and redness. This remedy suits those animals that tend to worsen in the wind and have skin issues with the change of seasons.Viola tri is particularly beneficial when addressing itchiness that pops up over different parts of the body. In addition, it also helps stimulate detoxification. Comocladia helps calm commonly inflamed or irritated tissue, while Chamomilla suits those animals that tend to rub and try to scratch during the day but even more frequently in the evening. Lastly, Cina can be used to support the skin from the inside out and is frequently recommended for horses that tend to twitch and jump in an agitated.
Keeping Flies at bay: When addressing Sweet Itch, keep in mind how irritating and bothersome it may be for your horse to have flies settle on already irritated skin. Natural fly repellents can ward of these pests, without the harsh chemicals used in conventional solutions. Many plants and herbs have been shown to have natural properties that flies find repulsive, thus keeping them deterred!