Sweet Itch
Sweet Itch
Sweet Itch is a hypersensitivity reaction to the bite of the midge which produces skin irritation that leads to rubbing, scratching and biting of affected areas, resulting in hair loss and skin damage. In severe cases the whole body may be affected but the most commonly affected areas are the mane, tail and face. The disease follows a seasonal pattern with ponies being affected during the midge season from March to November. Native ponies are most commonly affected but all breeds and types can develop the allergy. Severe cases have signs all year.
Horse affected by sweet itch
Treatment / Prevention
1. Prevent midges biting
Avoid the midges
- Stable at times of highest midge activity i.e. dawn and dusk.
- Choose paddocks in well drained, windy areas with no trees or rotting vegetation and away from water courses.
Provide a barrier to the midges
- The use of close fitting cover up rugs are very successful e.g. the Boett Blanket and masks to cover the face.
- Thick Vaseline/cream barrier can provide a deterrent in the groin area.
Repel the midges
- Fly repellents especially those containing DEET can be useful to repel midges but are not nearly as successful as the barrier method.
2. Reduce the hypersensitivity reaction
Topical lotions/ cream to reduce the itching
- Tea tree oil is often used as a natural anti-itch lotion and steroid based creams can be very effective if only a small area needs treating.
In-feed supplements
- such as Cavalesse® can be effective at reducing the hypersensivity reaction.
Steroid anti-inflammatories
- These are very effective at reducing the itching and hypersensivity reaction but can carry a low risk of laminitis so may not be suitable.
Desensitisation
- These treatments use initial tiny doses of midge saliva extract then ever increasing doses of allergen are injected. This has been successful in some cases.
3. Prevent scratching
Fence off all scratching posts
- Turn out in paddock fenced by electric fence to reduce the skin trauma from scratching. It is important to electric fence off all gates, trees and non-electrified fencing
Key points
- Sweet itch is a widespread problem, about one in twenty horses in the UK are affected.
- Treatment is aimed at controlling the problem - there is currently no effective cure.
- Treatment must be started early each year before the midges first appear.
- Cover-up rugs are probably the most effective single treatment option but they must fit very closely and have a belly panel.
- Measures must be started prior to the midge season to prevent the condition from becoming established.
- It is likely that there is a genetic predisposition so affected individuals should not be used for breeding.