Insect Bite Hypersensitivity

The flies are out again and it seems to be a bad fly season. Even worse, your horse’s reaction is worse than you’ve ever seen it. Instead of little bumps from fly bites, your poor boy has good-sized welts. You’ve tried fly sprays, fly sheets, and fly traps, but the problem persists.

What are some of the options?


 Identify the offenders and minimize their effect on your horse

In order to best help your horse, it’s important to identify the offender. Usually, it’s flies, but it could also be bites from other insects, such as fire ants, chiggers, mosquitos, or bees. If you find that the offender is from ant bites, eradicating them is the quickest way to resolve the issue.

Continued use of fly sheets, fly masks, and fly leg protection is prudent. Although it won’t help the existing welts, it can reduce the number of new ones that occur.

Hives can also occur when horses have an issue with some ingredients in their feed or supplements. It's important not to confuse the reaction to fly bites with a reaction that may look similar, but is due to ingredients in their feed. Verify that the feed is not the problem by doing an elimination test.

Treat topically

Welts can be painful, or they may be itchy. It’s important to wash your horse thoroughly to remove any allergens that can cause contact dermatitis. Washing is also useful to remove sweat, which can attract biting insects. It’s important to use a hypo-allergenic shampoo when washing.

After washing, some people have found it helpful to dab the skin with witch hazel, which is available at your local pharmacy, Walmart, or Amazon. Witch hazel has been shown to reduce inflammation and also helps soothe itchiness.

Support your horse with supplements

Once the hives occur, it’s very difficult to get the immune response under control. However, there are supplements which can help support the horse. Of course, these are more effective prior to a full-blown immune and inflammatory response. But it’s important to remember that they are one additional tool to help support your horse.

Spirulina: Once your horse is accustomed to the smell and taste, the recommended serving size is 1/8 cup, twice a day. Or if you only go to the barn once per day, ¼ cup once a day.

Chondroitin sulfate: Recommended serving size is 5-10 grams, twice per day.

Quercetin: Recommended serving size is 5 grams, twice per day.

Turmeric: Recommended serving size is 2 grams, twice per day.

MSM: Recommended serving size is 10 grams, twice per day.

You may use these in combination with each other.

Veterinary Care

Work with your veterinarian to discover any illness that may make your horse more susceptible to a disproportionate immune response. Treat underlying diseases, such as Lyme disease, filariasis, Cushing’s disease, or insulin resistance. Untreated or undertreated underlying conditions will make it more difficult to control the hives.

Your veterinarian may determine that prescription drugs are the most prudent course of action. This could include anti-histamines, such as hydroxyzine, or your vet may determine that steroids, such as prednisolone or dexamethasone is warranted. Your vet will know the risks associated with steroids.

Be persistent

Knowing that hives is already a runaway train, it’s important to be persistent in your efforts to help your horse. Treating hives is like trying to put out a forest fire with a garden hose. Results are not likely to occur quickly.

We do the best we can for our horses. Take a deep breath with treating hives.

Disclaimer: Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition.

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