What should I check if my horse’s skin is red and puffy after fly bites?

Read time: 3 minutes

Overview

If your horse’s skin is red and puffy after fly bites, the most likely cause is a local skin reaction to the bite itself. It may settle on its own, but it’s sensible to check the area closely for anything that suggests the skin is more irritated, infected, or reacting more strongly than expected.

There can be several reasons for the swelling, so it’s usually about monitoring the pattern, keeping the area clean, and watching whether your horse stays comfortable.

Things To Check

1. Check where the redness and puffiness are. Is it just around a few bites, or is it spreading beyond the bite area?

2. Look for heat, pain, broken skin, scabs or any discharge, as these can suggest the skin is more irritated.

3. Notice whether your horse is rubbing, stamping, or seeming bothered by the area, which can make the reaction worse.

4. Check whether the swelling appeared quickly after turnout or grooming, or whether it has built up over time.

5. Feel for firm lumps or a more general soft swelling, as the pattern can help you judge whether it’s settling or changing.

6. Look over the rest of the horse for other bites, hives, or itchy patches, especially around the face, belly, mane or tail.

7. Check for any signs your horse seems unwell overall, such as dullness, stiffness or not wanting to be handled.

Common Causes

The most common cause is a normal local reaction to fly bites. Some horses react more strongly than others, and the skin can look red, puffy and irritated for a short time.

Repeated biting or scratching can make the skin look worse and stay swollen for longer, especially in warm weather or when flies are active.

Less commonly, the area may be becoming inflamed from rubbing, contaminated by dirt, or involved in a more general skin allergy-type reaction such as hives.

What To Do

Keep a close eye on the area and note whether it is improving over a few hours or by the next day.

If the skin is dirty, gently clean it using routine safe care and avoid scrubbing, as that can make the irritation worse.

Try to reduce further fly exposure by checking turnout times, rugs, headcollars and stable areas where flies are building up.

Discourage rubbing where possible, since that can turn a mild reaction into a more obvious sore patch.

If the swelling keeps spreading, becomes painful, or doesn’t start to settle, it’s sensible to ask your vet for advice.

Products That May Help

If your horse is getting repeated fly irritation, a summer care routine can help you stay on top of grooming, skin checks and day-to-day management during fly season.

Horse Fly Sprays & Summer Care

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