My horse has hives; what should I do? I heard that question so many times. Hives (urticaria) consists of small bumps, swellings or wheals that appear on a horse’s skin for a number of reasons. The bumps are typically flat, round and about half an inch across, but sometimes they may appear in groups that spread over as much is eight inches of a horse’s skin.
Sometimes these bumps are itchy, and sometimes they are not. Although it’s possible for them to develop on any part of a horse, they usually show up on the back and neck and/or the flanks and legs.
How Can You Prevent Hives?
It’s hard to know how to prevent hives because it’s hard to know what causes them. The causes of hives are many and mysterious.
Some horses experience them seasonally, others experience them when exposed to a specific allergen, still others may get hives from pressure or contact.
Among the suspected causes are:
- Ingestion of food allergens
- Extremes in temperature
- Contact with allergens
- Pressure on the skin
- Pollen inhalation
- Insect bites
If your horse’s hives show up when you’ve made any sort of change in routine, that can be your first clue to the cause of the problem.
For example, if you started using a different kind of bedding or started turning your horse out in a different pasture, that may be the culprit.
Changes in equipment, tack, grain, hay and care products such as shampoo may also cause hives.
If you find that your horse experiences hives after some sort of change in routine, you should stop the new additions immediately and see if your horse recovers from the problem.
Following this, you can gradually add new items and activities back into your horse’s routine one at a time to try to identify exactly what is causing the problem.
What If The Hives Don’t Go Away?
Sometimes an attack of hives is a one-off, and sometimes they return again and again. Left untreated, chronic hives can become very problematic because the bumps may begin seeping and crusting over.
This can lead to a lot of discomfort and secondary bacterial infections. Recurring attacks of hives can also affect your horse’s behavior by causing chronic discomfort which may lead to bouts of restlessness and anxiety.
If hives persist, you must consult with your veterinarian. He or she may refer you to an equine dermatologist or to an internal medicine specialist to perform some testing.
Intradermal skin testing is very useful for determining exactly what is causing your horse to experience an allergic reaction; however, if your horse’s problem is caused by diet, neither blood testing nor skin testing will help.
You’ll simply have to go through a process of elimination to figure out exactly what the problem is.
Read also: My Horse Ate Chicken Feed
How Can Hives Be Treated?
Once the cause of your horse’s hives is determined, you will naturally want to remove the allergens from his daily routine.
If this does not resolve the problem completely, your vet may recommend supplements such as MSM and omega-3 fatty acids.
He or she may also recommend simple care such as rinsing the skin with cool water daily.
In addition to treating your horse for hives, you should also evaluate your environment and make adjustments to help eliminate potential causes of hives.
For example, you may wish to take very aggressive steps to control flies in the environment by making use of items and actions such as:
- Elimination of standing water in puddles, feed pans and the like
- Introduction of beneficial insects such as parasitic wasps
- The addition of diatomaceous earth to your horse’s diet
- Fly masks, sheets, therapy rugs, and boots for your horse
- A timed fly spray system in your barn
- Mesh curtains and fans in the barn
- Good manure management
In more severe cases, medications such as antihistamines and steroids are often recommended.
If your horse’s allergies are caused by environmental conditions beyond your control (e.g. grass or tree pollen or the ubiquitous biting midge) your vet may recommend personalized immunotherapy.
This may consist of oral drops or a series of injections.
Ask The Vet – Pressure Hives In Horses
Frequently Asked Questions
Hives are often caused by an allergic reaction to insect stings or bites. Allergies to feed, forage, environmental factors or to medications may also cause hives. Sometimes hives can be caused by ringworm infection. Inflamed blood vessels in the skin (vasculitis) may also cause hives.
A number of pasture weeds can cause hives if they are consumed. Among them are leafy spurge, wooly vetch, horseweed, western juniper and buttercup. Luckily, these plants are not favored by horses, so they are usually not consumed.
Rain rot, which is a bacterial infection, can look like hives. This condition typically manifests as bumps and scabs on a horse’s upper neck and along the topline.
You can try folk treatments, such as cold compresses and rinsing with cool water and baking soda. Antihistamines may also be helpful. The plant antioxidant, quercetin, is a natural antihistamine that is often used in horses. Another choice is tripelennamine. Some people even use Benadryl, but before you use anything, you should contact your vet.
Because hives, rain rot and a number of other conditions can look very much alike, you should always consult your vet. Treatments for hives will not help with rain rot and vice-versa.