Many horse owners recognise the sight: the horse runs around restlessly, suffering from excruciating itchiness or even rubbing off its long hair. The cause is sweet itch, which, as an allergy-induced dermatitis, is one of the most common skin disorders in horses. The unusual agitation and the excessive rubbing are consequences of sweet itch that often leave owners helpless. What treatment is available, what can be done to soothe the itching and how does sweet itch develop in the first place?
Causes and triggers of sweet itch
Sweet itch is the result of an allergic reaction caused by the saliva of insects, especially black flies and gnats or Culex mosquitoes. It is not the painful bite itself, but the saliva that leads to the development of pustules and itchiness. It enters the horse’s organism and causes allergic dermatitis — sweet itch. Some breeds are more frequently affected, especially Icelandic horses, but also Haflingers and Norwegians.
Symptoms – How to recognise sweet itch in horses
The symptoms vary in severity depending on the extent of the allergic reaction. The first signs often go unnoticed. The appearance of pustules, scaly skin irritations or small nodules are initially not very pronounced and therefore hardly noticeable. Usually, the problem only becomes critical for owners and riders when the horse becomes increasingly restless and starts to rub excessively. Sweet itch occurs mainly in areas where the hair is vertically erect, for example, on the mane crest, tail rump, belly and croup. Due to the permanent rubbing, open, sometimes purulent eczema develops, accompanied by hair loss.
Treatment of sweet itch in horses
Treating sweet itch is hard and mainly focuses on alleviating the symptoms. Various lotions, ointments, creams and oils are now available, which are to be applied daily to the skin and promise to cure the eczema. However, it is always best to consult a vet, especially since there is no generally effective patent remedy for sweet itch. In severe cases, a cortisone treatment may be considered.
Feeding & management — How to prevent sweet itch
More important, however, is the right type of prevention to stop sweet itch from occurring in the first place. Care should be taken to provide the necessary protection against bites by using insect repellents and so-called sweet itch rugs. Black flies and other insects like it damp and windless and are more active at dusk. Consequently, horses should only be out to pasture during the day in dry and rather windy weather conditions, if possible. Feeding is also an essential prerequisite for a well-functioning metabolism. Nutritional deficiencies negatively affect the sensitivity to allergic reactions. Deficits due to a lack of vitamins or trace elements, therefore, increase the risk of skin diseases.