Sweet itch

Last Updated on February 19, 2022 by Allison Price

Sweet itching is one of the most common allergies that horses suffer from in the UK. Learn how to prevent and treat it.

What is sweet itching?

Sweet itch can be caused by allergic reactions to bites from midges and mosquitos. It can affect any horse or pony, regardless of breed or age. However, research has shown that it is more common in certain native breeds. Sweet itching is the most common allergy skin disease in the UK, affecting approximately 5% of the horse population.

There are many types of mosquitos and midges that can cause hypersensitivity. However, the most common in the UK is the Simulium (black fly) and Culicoides (midge). Sweet itch is not a seasonal condition. These biting insects can be active from March through November.

Pruritis is the name for the itching caused by insect bite allergies. The term sweet itch literally refers to the sensation that horses or ponies feel when they react to bites. This condition can be as mild as a horse scratching at a tree or scratching at his own skin, which can lead to self-trauma. Many cases also have secondary infections and other allergens.

How to spot it

Sweet itch can be easily detected early and treated promptly. It is important to determine if your pony or horse is suffering from sweet itching. Sweet itch may not be caused solely by midges, but there are other allergens that can cause it.

Sweet Itch on Horses

What are the signs?

Sweet itch symptoms can vary from one horse to the next. Some horses may be very sensitive to just one or two bites. Others may not experience any reaction at all.

  • The most common areas of itching are the neck, tail and mane. However, these areas aren’t the only ones affected. Horses with severe skin conditions may rub and bite at their skin whenever they can.
  • The affected areas may appear lumpy, scaly, and often inflamed or too hot to touch. However you might also notice areas where hair is ruffled or rubbed.
  • Hair loss, bleeding and thickening can be caused by self-trauma due to scratching.
  • It is possible for skin to appear scurfy, or dull in spots. This is something you should be aware of.
  • Horses can become restless, and in extreme cases, may lose weight.
  • Regular grooming is a great way to watch your horse’s skin and identify any signs of illness so that you can take the appropriate actions.

How can sweet itch be diagnosed?

You should first try to prevent your horse from being bitten if you suspect sweet itch. Then, contact your veterinarian for further advice.

You may be asked by your vet to perform intradermal allergy testing. To test for allergic reactions, the vet will inject midge extracts to the skin. You can also check for other allergens to narrow down possible causes. There are a few blood tests that claim to be able detect allergies, but they have limited support or reliability.

What are the best times to be alert for symptoms?

Sweet itch is caused by mosquitos and midges. This is the best time to check for signs that your horse may be suffering. Sweet itch is usually a seasonal condition, but some horses will have more severe symptoms all year.

What can you do to stop sweet itching?

Sweet itch is preventable.

  • There are many fly-rugs on the market, and they can be tailored to fit a variety of budgets as well as the severity and reactions of horses to biting insects. Fly rugs are required for horses with severe allergies. They should be worn 24/7 by the most severely affected horses. Some rugs cover only the neck, under belly, and body area while others will completely encase the horse’s skin. This is to protect it from biting insects.
  • There are many options for fly repellents. While a traditional cream or spray application is always an option, you might also consider repellent tags and bands to help control mosquitos and midges. Permethrin-based or pyrethroid-based ingredients are usually the most effective. DEET can be effective but may cause soreness in horses. Avon Skin-so-Soft, which is less-chemical, can be used to treat sunburnt skin on hot sunny days.
  • Biting insects are most common at dawn, early evening, or dusk. If possible, keep your horse stabled during these times. It will depend on where you live, what time of the year it is and what works best for you. You would want to be able to come back every day to put the horse or let them out, but this is not possible in an ideal world. However, work and other commitments can make it difficult.
  • Ultrafine (60 sq/in) midge screens can be used to cover windows and stable doors. They can also be very effective in keeping the insects away. Although this may seem extreme, sweet itch can be a serious condition. It is possible to get rid of all but one midge by placing it on a stable door or window.
  • You can use insecticide sprays in the stable area. It is also worth investing in fans to reduce midge burden.
  • After feeding, female midges lay eggs in soft mud. Avoid areas that have standing water. Natural windswept areas will have a lower population of midges than those that are sheltered and still. For the same reason, avoid thick tree line. Although a paddock located on top of a hilly area would be ideal, it is unlikely that many people will have the opportunity to access it. It may be worthwhile fencing any areas that are particularly low or protected in your field so that your horse can’t access them.

How can sweet itching be managed or treated?

There is no cure for sweet itching. It is best to take preventative measures to avoid the midges from biting.

  • In the short-term, steroids can provide relief from clinical signs such as skin irritation and itching. Steroids can increase the risk for laminitis over the long-term so they should not be used as a permanent solution.
  • Antihistamines may be helpful in some cases. However, they must not be used in large quantities. This can make them expensive and ineffective. These should only be used as directed by your veterinarian.
  • Anti-itch shampoos are effective in relieving itching. Look for ones that contain anti-histamines, oatmeal, or local anaesthetics. You can also use ice or cold water to soothe the area temporarily.
  • Research has shown that omega-6/3 fatty acids may reduce itching. It is worth considering flax seed oil or evening primrose oils to get some relief.
  • Cavalesse, a supplement containing Nicotinamide that is administered orally, has been proven to partially relieve clinical signs.
  • “Itchy Horse” is an organization that has taken over the National Sweet Itch Centre. It does not have a commercial product, but it does have some products like Bioeos capsules.

Different products and solutions will work differently for different horses. This means that there is some trial and error to determine what works best for you and your horse.

Preventative measures combined with appropriate treatment will manage the problem and make the horse’s life easier.

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!