What is sweet itch?  Well, you may also know it by any of the following other names:


  • Summer equine dermatitis
  • Recurrent seasonal pruritis
  • Summer eczema
  • Insect bite hypersensitivity (IBH)
  • Queensland itch


It’s known as Queensland itch because it’s estimated that 60% of horses in this part of Australia suffer from it.  Other parts of the world hover at about 5-20%. 

Sweet itch is a skin condition stemming from the allergic reaction to the bite of the midge, genus Culicoides, aka no-see-ums.  This tiny bug (about 4 mm long for a big one) lives on blood for part of it’s life cycle and will feed from your horse.  Typically, the midges bite around the tail, dorsal midline (spine) and mane area. 


The subsequent allergic reaction to the bite, which is an immune response in your horse, triggers a series of events that can be hard to stop.  First there is insane itching, which leads to hair loss from all the scratching.  You will also then have more itching, more scratching, and eventually open and bleeding sores that can become infected.  



This horse's mane is almost gone due to rubbing.  She's about a few days away from having open sores.


Fortunately, there are some things that we can do to prevent this and help reverse the damage.  First is prevention.  Fly spray needs to become your friend, look for permethrins and benzyl benzoate as ingredients.  Also make friends with a fly sheet.  There are several companies that makes a fly sheet specific for midges, which basically covers your whole horse except the head and legs.  Tail head, belly, neck, and face are all covered with awesomely designed panels and velcro and elastic.  Your horse will appear to be in a bio-hazard suit, but that's exactly what he needs.  


You also need to consult with your Veterinarian about the actual diagnosis of this, so that the appropriate medicated shampoos and topical creams can be prescribed.  There are a lot of other things that can cause excessive itching and subsequent rubbing.  Getting your Veterinarian involved in finding the cause will enhance your chances of a successful treatment.  You and your Veterinarian can also discuss the use of antihistamines, which would be added to his food, or systemic steroids, although steroids carry great risks for laminitis in some horses.  


Sores and bald patches on this horse's face from sweet itch.



More mane hair loss, showing bare skin.  A few more days of rubbing and this horse's skin could break open.  Then the scab, rub, open sore cycle starts.  


Usually, some sort of medicated shampoo and topical cream will help your horse out tremendously, and the fly spray combined with the fly sheet/tail and neck cover combo will help the healing.  Be warned that some prescriptions, even for topical medications, will test positive at shows.  


There is also the option to add flax to your horse’s diet, some studies have suggested that the extra omega-3 fatty acids in flax really help his immune response and healing.  (Omega-3 fatty acids are known ant-inflammatory agents).  Check with your Veterinarian for dosages. 


As far as barn management goes, you can do a few things here, also.  Keep your affected horses tucked away in the barn during peak midge activity hours (early morning and dusk).  Use super fine screen around their stalls to keep the buggers away. Don’t forget to cover the top of the stall.  You can also use a fan in the stall during those times of the day.


The fatty acid based fly control sprays may also help with sweet itch!


Midges like to hang out near water, so have a barn wide hunt for water sources that can be drained.  Fix leaky sprinklers that puddle, dump standing water, and work on drainage.  Move affected horses away from standing or stagnant water sources. 

The bottom line is that once the allergic reaction starts, the cycle is hard to break because as your horse itches, he creates sores.  Those become itchy, so he rubs more.  Endless cycle.


What have you done to help a horse with sweet itch?