Sweet Itch / Queensland Itch

Queensland Itch, Sweet Itch and Equine Allergic Dermatitis are names for a distressing skin condition which affects some horses in summer and spring months throughout the world.  In Australia it is commonly known as Queensland itch as it affects 60% of horses along the East Coast.


Queensland Itch is thought to be caused by a hypersensitivity to the bites of the tiny flies, Culicoides.  It occurs in varying degrees of severity in horses of various breeds and ages. English breeds have been reported to be more susceptible than Arabic breeds and the incidence of susceptibility has been reported to increase with age.


Research suggests the cause is an allergic reaction to chemicals in the saliva of the midge. When this reaction occurs, specific chemicals are released in the skin. These chemicals cause a localised irritation, which the horse will try to scratch and rub. 


The midges tend to feed on the horse at specific sites.  They most commonly feed around the tail head, withers, and base of the mane.  The midges are most active at dawn and dusk and like to breed on wet land, and around dams, rivers and lakes. 


The effect of Queensland Itch can be minimised by protecting your horse from the midges, removing the midges and treating the itching:



Stabling the horse from 4pm until 7am during summer months to help limit contact between the horse and the midges.  Culicoides flies are most active at dawn and dusk.


In addition to stabling, closing doors and gauzing windows has had a 14 fold decrease in fly numbers in research on the Culicoides bolitinos and Culicoides imicola flies.

Culicoides flies breed near still stagnant water.  It has been reported that they do not fly more than a few hundred meters from their breeding area.  Stabling and paddocking horses more than 500 meters from the Culicoides breeding ground may reduce exposure to the flies.


Rugging and hooding susceptible horses decreases the exposed area of the horse they can bite.



Using regular fly repellent.  There are a variety of repellents on the market.  


Insect repellents can be sprayed on and need to be constantly reapplied.  


There is a pour-on repellent available which is absorbed into the horses bloodstream and has been successful in some horses.  You should be able to obtain this at your local saddlery or from your equine veterinarian. 



Feeding Omega 3 Oils.  MITAVITE PERFORMA 3 Oil contains Omega 3 oils which have been shown to decrease inflammation in horses.  Recent research suggests feeding Omega 3 oils may be beneficial for some horses with Queensland itch. We would suggest feeding 150-200ml per day.


Corticosteroids have been used to treat skin allergies.  Steroids do have side effects and their use should be prescribed and monitored by an equine veterinarian.


Trials with immunotherapy have given mixed success 


Not all itching or rubbing in horses is caused by “Sweet Itch.  Your equine veterinarian should be able to accurately diagnose your horses condition and if it is Sweet/Queensland Itch suggest an appropriate animal-specific insect repellent and soothing skin preparation to help control itching and aid healing sores.