Equine Allergy Testing

Hives can be so severe that the horse rubs itself raw trying to get relief from the itch.

For those owners whose horses are plagued with allergies, few long-term options exist to effectively manage the problem.

About 90% of the time, allergies manifest themselves in horses as hives. When they flare up, the vet will often prescribe antihistamines and/or corticosteroids to combat them. Sometimes antihistamines work to reduce the severity of the hives, yet many times cannot resolve them completely. Corticosteroids, on the other hand, work exquisitely to make hives disappear within hours. Cold-water therapy or ice packs can also be helpful in slowing down an allergic reaction. The bottom line: All of these therapies really only work well for the short term.

Long-term corticosteroid therapy, while possible, can be dangerous. We know that corticosteroids can induce many metabolic changes in the horse that can result in some serious problems. Laminitis, gastric and colonic ulcers, as well as immune suppression are on the list. With that said, corticosteroids can be a God-send in relieving an itchy horse of his allergies. But, are there any safer options?

The answer is YES. Veterinarians have the ability to perform Serum IgE testing and hyposensitization that can provide long-term relief from allergies. IgE is an immunoglobulin found only in mammals that plays a pivotal role in hypersensitivity (allergic) reactions. Horses plagued with hives often have elevated IgE levels to dozens of allergens prevalent in the environment. Because of so many triggers, the horse’s immune system remains hyperactive on an ongoing basis.

Labs such as Spectrum Labs offer comprehensive test kits that test for common regional allergens. Testing is simple – It just involves drawing 1 blood tube sample and shipping it at room temperature to the testing facility. The Spot Platinum equine assay represents the most comprehensive allergy testing available, with a total of 86 of the most common allergens in the region that the sample is shipped from, including grasses, trees, weeds and shrubs, common barn allergens, grain mixes, foods (such as alfalfa, barley, corn, linseed, milo, oats, etc.), molds and biting insects common to horses. Also, if you suspect that a specific trigger is causing the allergies, you may request that a test be run for it.

Once testing is complete, the lab will send a report that details the allergy profile for your horse. It will assist you in eliminating or minimizing allergens in your horse’s environment. But what if that isn’t enough? It just so happens that you can use your horse’s own serum to formulate a hyposensitization treatment regimen. It is actually quite simple – the lab will titrate low doses of all of the allergens that your horse is sensitive to (up to 21 standard, with additional allergens costing extra) into an injectable solution. Shots are administered over a 9-month period and administered in increasing doses as well as gradual increases in concentration. This method serves to gradually habituate the horse’s system to the presence of the allergens, thus creating a tolerance for them. The initial 9-month period of hyposensitization is followed by monthly maintenance shots.

While this process does not work quickly, it may prove to be a viable option for horses and owners who are plagued with allergies year after year. It is surprising cost effective and has either cured or reduced allergic reactions significantly in the vast majority of horses that receive it. With adherence to the treatment schedule, one can expect an excellent chance of elimination of or reduced dependence on steroid drugs. Improvement in most cases is seen after 3-5 months of treatment, at which stage shots are given monthly.

To access more information about SPOT serum IgE testing, click here.

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