Sweet Itch or Culiccides Hypersensitivity, is caused by an allergic response to the bites of Culiccoides Midges. Specific allergens in the saliva of many different species of Culicoides Midges cause a hypersensitivity reaction in horses and ponies.
Sweet Itch is most prevalent during spring and summer months
The allergic reaction develops at the site where the insects feed. Affected areas show skin lesions usually affecting the mane, ears, head, tail and back. The lesions are characterised by intense itching, which results in considerable trauma, the rubbing causes broken hairs, bald patches, thickened skin, and sometimes broken and bleeding skin from which secondary infections may occur.
Sweet Itch is not contagious, but if a high midge population is present more than one animal in a herd could well be effected.
A hereditary predisposition is thought by many to be a factor, however research to identify the gene /s responsible so far is inconclusive
Estimates vary but it is thought that approximately 5% of the UK equine population suffers from Sweet Itch.
The only effective form of treatment is to prevent further insect bites. Insecticides and repellents such as Permethrins and Benzyl Benzoate have been used with success. Midge numbers are often greater in areas with low air flow, near water, ponds, bogs, and wet ground for example, these are areas that are ideal for the Cullicoides to breed, moving the animal away from such areas to a more exposed windy site will help. Stabling the animal at the times of the day when the midges are most prevalent (dawn & dusk ) will also help. Although for serious cases stabling is probably best avoided. Other methods that are used include :- fly rugs & hoods, feed supplements, antihistamines ( these may have side effects ), and herbal remedies. In some cases Steroids can be a short term solution. . The problem is that no one method of treatment seems to be universally effective, what works for one pony may not work for another.