Around 3% of horses in the UK are affected by sweet itch, which is an allergic reaction to the saliva from the bite of the Culicoides, biting midges. Histamine is then produced by the body’s immune system which causes intense itching so the animal rubs and scratches which can result in hair loss, broken skin, thickening of the skin and sores which may become infected if not managed. Other signs can include lethargy or agitation, lack of concentration and head shaking. There is no cure, it can only be managed.
There are approximately 20 species of Culicoides present in the UK and the tiny fly is active from March to October but particularly prevalent from May to September. However, the climate is 
playing havoc with the seasons, making it warmer and extending the midge’s breeding time. It is important therefore, to keep the midges away from the animal so fly repellent, rugs and screens are useful along with supplements and ointment to soothe the discomfort. Start early before the flies are around – awareness is critical to control the intensity.
The midges are at their most active at dawn and dusk and they breed where there is water. Wet fields and even manure is sufficient. Sweet Itch tends to appear in horses between the ages of 1-5 years but there is evidence that stress can be a cause (for example illness, moving home etc) when an older animals develop Sweet Itch. Hereditary genes can play a factor as well as surroundings but sweet itch is not contagious. Any breed can be affected but it seems to be more prone in Icelandic and heavier horses. The top of the tail and the mane seem to be the worse affected areas. A swarm of midges can give up to 3000 bites an hour and they are attracted to carbon dioxide vapours and other chemicals released from from breath and skin. Only the females bite. It gives them protein and energy to produce their eggs. They do not like the wind, low temperatures or very dry conditions.
Tips to help manage Sweet Itch
- Application of fly spray twice a day (keep away from any open sores) click here to see.
- Application of lotion such as Z-Itch to aid in the control of sweet itch.
- Application of lotion to soothe click here to see.
- Use thick oils such as citronella to help as a barrier (keep away from any open sores)
- Use a full neck and belly rug (click here to see our stock)
- Avoid dusk ’til dawn grazing, when the midges are at their peak.
- Use a stable net fly screen.
- Put a fan in the stable to create air movement as midges cannot fly against a wind stronger than 5m.p.h.
- Use of antihistamine and feed supplements may be effective although high doses of antihistamine can cause drowsiness so check with your vet first.
- Avoid wet pasture and being near muck heaps.
We stock a range of products to help you manage sweet itch. Z-Itch is an effective pour on lotion which is best started before the beginning of the season but treatment can start at any time during the spring, summer and autumn.. It contains permethrin 40 mg/ml and is supplied in a bottle that features an integral measuring chamber, so there’s no need to use syringes or measuring cups to measure out how much is required. Just measure out the amount needed and pour equally along the horse’s mane and rump, avoiding the saddle area. Most horses require Z-itch just once a week although the amount of Z-itch required relates to the weight of the horse, and this impacts on how long a bottle will last. A 100kg horse requires 10ml per application, meaning a 250ml bottle will last for 25 weeks. The maximum amount required for horses of 500kg is 40ml. At this rate, a 250ml bottle will last for 6 weeks. Click here to see Z-Itch.
We also stock Fly Rugs, Dermoline Sweet Itch Lotion, and products to help rebuild manes and tails, such as Mega-Tek and Pig Oil.
