Home Β» All Posts Β» Horse Care Β» Health Β» Understanding Sweet Itch in Horses: Symptoms & Causes

Understanding Sweet Itch in Horses: Symptoms & Causes

Scottie wearing his fly rug to protect is manky armpit

Sweet itch, also known as summer eczema or equine insect hypersensitivity, is a common yet distressing condition affecting horses, particularly over the Summer. We’ve all known horses who “have a touch of sweet itch” where they are often seen with bald manes and tails from rubbing. But it can be an absolute nightmare for both horse and owner. In this post, we will look at the cause and common symptoms of Sweet Itch.

What is Sweet Itch?

Sweet itch is an allergic reaction in horses caused by the bites of certain species of midges, primarily the Culicoides midge. If you have ever had a bad reaction to an insect bite/sting, you can imagine how itchy and uncomfortable this condition can be. It’s believed to effect about 5% of the UK horse population. Luckily, it is usually a seasonal condition, often flaring up during spring and summer when these biting insects are most active.

What Does Sweet Itch Look Like?

The symptoms of sweet itch are unmistakable once you know what to look for. Here are the key signs:

  • Intense Itching and Scratching: Horses with sweet itch will often be seen rubbing against fences, trees, or stable walls to relieve the intense itching. This can lead to hair loss and damaged skin.
  • Bald Patches: The constant scratching and rubbing result in bald patches, especially around the mane, tail, withers, and belly.
  • Skin Lesions: These can range from mild to severe and include broken skin, open sores, and scabs. Over time, the skin may thicken and darken in affected areas.
  • Crusting and Scaling: As the skin attempts to heal, it may become crusty and scaly. Secondary infections are also common due to the open sores created by scratching.
Horse suffering with sweet itch
Credit Tsaag Valren, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Horse suffering with sweet itch
Credit Tsaag Valren, CC BY-SA 4.0

What Causes Sweet Itch?

The primary cause of sweet itch is an allergic reaction to the saliva of biting midges, particularly from the Culicoides species. Here’s a closer look at the contributing factors:

  • Midge Activity: These tiny insects are most active during dawn and dusk in warmer weather, typically from April to October in the UK. They thrive in damp, marshy environments where they breed.
  • Allergic Reaction: When a midge bites a horse, it injects saliva into the skin. Horses with sweet itch are hypersensitive to proteins in the midge saliva, triggering an exaggerated immune response that leads to itching and inflammation.
  • Genetics: Some horses are more prone to sweet itch due to their genetic makeup. Breeds such as Icelandic Horses, which have not evolved with midges, tend to be more susceptible.

Scottie’s Sweet Itch

The past few years Scottie has had the occasional bad reaction to an insect bite/sting. We’ve had an ear, an armpit and a bum cheek. Each time once it healed, that was it for the summer. But this year, the insects have been horrible and it seems to have developed into a more consistent problem. He is regularly reacting to insect bites in his girth area, I suspect midges due to it happening when the midges have been bad. It’s definitely been a learning curve for us and I have been doing a lot of research into how to manage the condition.

Because Sweet Itch is an allergy, there isn’t a cure. But recognising the signs and understanding the causes is the first step in tackling the problem. Next time we will be looking at preventative management and soothing treatments for when your horse does develop sweet itch.

Last Updated on 07/06/2024

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.