Sweet-Itch is caused by Midges (Culicoides species) biting the horse.


Certain horses react to the antigens in the midge’s saliva causing intense itching. This is normally concentrated around the tail base and mane and the most obvious clinical signs are rubbing, itching and hair loss in these areas. Over time chronic cases get thickened skin and permanent hair loss due to the damaged follicles.

It is very important to anticipate sweet itch before it occurs as it is much easier to prevent than treat an established problem. True sweet itch is seasonal and coincides with the midge season in spring/summer.

●Avoid turning the horse out near areas that attract midges such as water sources, muck heaps, lakes, streams, marshland and warm muggy areas.

●Midges do not like windy areas so putting a fan by the stable will deter them. Midge nets over the stable door/windows can also be used.

●Midges are most active during dawn and dusk so stable the horse during these periods.

●A full fly-rug including belly, tail and face covering will protect the horse to a certain extent from midge bites.

●Good fly repellent applied liberally daily – the best ‘off the shelf’ repellent is Coopers fly spray which was re-issued last year.

●‘Cavelesse’ - an oral treatment; mainly vitamin B3, which may help prevent clinical signs by down regulating the immune response and improving the skin barrier.

Once the clinical signs are apparent, breaking the itching cycle is much harder. Treatment involves implementation of the above procedures, stabling the horse if the condition is severe and then your vet may decide to use the following treatments: 

● Antihistamines - e.g. Chlorpheniramine (Piriton) or Hydroxyzine (Atarax) can be used, but the effect is minimal and may cause sedation.

● Steroids – very effective at breaking the ‘itch/scratch’ cycle and reducing inflammation. Not suitable for all horses as there may be a risk of laminitis.

● Veterinary products ‘Switch’ and ‘Deosect’ are strong fly repellents which are very effective and last longer than regular fly spray.

● In severe cases antibiotics and anti-inflammatories to treat secondary  infection and inflammation may be needed.

● Dietary fatty acids such as linseed or flax oil may improve skin condition and barrier to infection.


Veterinary advice in this magazine is provided as a general guide and you should always seek professional advice