What is Sweet Itch?
Sweet itch is the lay man’s term for Summer seasonal recurrent dermatitis (SSRD). Simply defined, sweet itch is the allergic reaction horses develop to the Saliva of Culicoides midge, the biting gnat. Most people refer to the biting gnat as “no-see-ums.” Biting gnats are quite troublesome and they are active between April and October. You will mostly find them in places where water is stagnant such as marshes and ponds. They can go as far as half a mile in search of a good meal. Biting gnats usually disappear in the winter period provided the temperate is cold enough. As such, those who want to buy horses around this time should be aware of the risk of buying horses that has already been infected with sweet itch.
Sweet Itch is a skin problem that affects thousands of ponies, donkeys, and horses in many countries of the world. Sweet itch affects virtually all types and breeds of horses and ponies, from heavyweight draft horses to tiny Shetland ponies.
Horses do not show any clinical signs after the first gnat bite until about 48 to 72 hours when they begin to show signs. The severity of your horse’s allergic reaction to biting gnat increases year after what as your horse becomes more sensitive to the saliva of the insect.
The commonest biting gnats are the dorsal feeders who enjoys their meal on the skin around the poll, ears, mane, tail head, rump and withers. The less common are the ventral feeders who wrecks havoc on the belly, chest and face.
What are the Clinical Signs of Sweet Itch in Horses?
The symptoms of sweet itch are glaring; horses that are affected by sweet itch will constantly rub the affected areas in an attempt to respond to the severe itching. In the early stage of the infection, the skin of the affected area is red and appears to be inflamed. Weeping sores and crusting may also be present in the early stage. The chronic stage is when the skin of the affected thickens, blackens and wrinkles.
The symptoms of severe sweet itch includes flaky dandruff, skin thickening and hair loss. Exudative dermatitis may also occur. If left untreated, sores can lead to secondary infection. Sweet itch affects the mane and the top of the tail, the forehead, ears, hips, withers and the neck are also affected. In severe cases, the sides of the head, the saddle area, the mid-line of the belly, legs, udder or sheath may also suffer. Bald patches that looks grey and ugly due to skin damage and hair loss may also appear on the horse’s body. There may also be permanent hair loss in the mane and tail area.
You may notice the horse swishing its tail vigorously, rolling frequently and making an attempt to rub its body against anything within its reach. The horse may pace endlessly to seek grooming from other horses. If the horse is confined behind electric fencing and there’s nothing within its reach to rub its body on, he may scratch his mane with his hind feet and bite his heels, flanks and tail vigorously. He may even go as far as dragging itself on the ground to scratch the belly.
There may be a change in temperament, frequent yawning and in-activeness as the horse may become impatient. He may also be agitated when the biting gnats are around and shake it’s head repeatedly.
How is Sweet Itch Diagnosed?
The diagnosis isn’t difficult given that the symptoms are strong indicators. If left untreated, symptoms can persist into winter and become more severe considering that the initial case wasn’t cleared up. Horses that develop sweet itch starts showing the symptoms between the ages of one and five.
Research shows that the stress of moving into a new home, the stress of recovering from a severe injury can contribute to the development of sweet itch.
Hereditary predisposition is also a factor that contributes to sweet itch in horses. The genes that are responsible can be identified at an early age. Environmental factors play an integral part too, that is where the horse was birthed (if it’s an adult already) where it lives are significant as the genetic makeup of the horse.
Sweet itch doesn’t spread from horse to horse though if condition favors the population of biting gnat in the field, more than one force will be affected. In the United Kingdom, sweet itch is listed as an unsoundness and is usually declared before a horse is sold.
What are the Measures to Take to Limit Exposure to This Bothersome Insects?
Some measures to take.
- You can start by fixing fine mesh screen in your paddock to keep the gnats away.
- Install ceiling and stall fans to keep the insects from hanging around.
- Keep your horses indoors an hour before and after dawn and dusk to limit exposure to the insects because that’s the time they feed actively.
- Your stables should be at least one mile away from swamps and marshes.
- Make sure you set up proper drainage in your paddock so stagnant water doesn’t accumulate
- Clean your water tanks and fill them with fresh water
- Get repellents and use insecticides to kill biting gnats. Also spray repellents on your horse to keep the insects away.
- Cover the hood and tail flap with a fly sheet. This will help to cover the vulnerable areas.
Treatment and Prevention of Sweet Itch in Horses
Begin treatment as soon as you notice the symptoms of sweet itch in your horse. The sooner you start the treatment, the better off your horse’s body will be. Much damage can be done to your horse’s body in just a short time if he starts rubbing tails and manes.
The moment you notice the first symptoms of sweet itch in your horse, take the necessary measures (as listed above) to limit your horse’s exposure to the biting gnats. Then follow our recommendation for the treatment of sweet itch in horses.