Sweet itch is caused by an allergic reaction to the saliva of the Cullicoides midge (the same midge involved in the transmission of the dreaded African Horse Sickness). The midges bite the horse, and in horses with allergic sensitivity they develop itching of the mane and tail and, in some cases, the face and the poll.
Itching tends to begin in summer, but can be present all year round. The level of severity varies from horse to horse – some horses will itch themselves until they are bald, whilst others will scratch until they break the skin which then can ulcer or get infected.
Prevention is based on reducing exposure to the midges. This involves the use of the same insect-repellent sprays and creams used for AHS prevention. Sweet itch fly rugs and fly masks can also be integral to prevention. Midges tend to congregate near stagnant water or in wooded areas, so try and avoid having your horses stand in paddocks near these kind of features. Horses affected with sweet itch, along with all horses during the AHS period, should be stabled at dawn and dusk when the midges are at their most active. Fans can be put up near stables to prevent midges approaching.
If your horse is severely affected; the skin is broken; the skin is hot or inflamed; or this is the first time that you have noticed a skin reaction in your horse, contact your vet immediately. If the itching continues despite preventative measures vets are able to prescribe injectable, oral and/or topical medications to make your horse more comfortable and reduce the reaction