A young horse named Sancho, who boards at the barn where I ride, is allergic to just about everything---grain found in feed, pollen, and even grass. These substances cause him to get itchy skin all over his body. Allergies are not common in horses, so I found it interesting that he is allergic to so many things, not just on or two things as is more common. The only things he can eat with getting itchy are alfalfa and oats.
An allergic reaction occurs when a horse eats or inhales something he is hypersensitive to, causing his body to produce too much antibodies and histamines. This can cause itching, as in Sancho's case, hives, hair loss, and/or heaves. Many things can cause these reactions, not just allergies, so try looking into other problems before you label the condition as allergies. If allergies do turn out to be the culprit, find out what the horse is allergic to and try to keep him away from that substance as much as possible. This can be hard in Sancho's case, or if your horse is allergic to something commonly found in the environment(pollen, for instance), but do your best.
The saliva in insect bites is the most common thing for horses to be allergic to. Sweet itch is an example of this. Signs of an allergic reaction to insect bites include bites on the skin, itchy skin, and inflamed, scabby skin. Try using ointments or sprays to reduce itching. If you like essential oils, you can mix several drops of one or more of the following oils with distilled water in a spritz bottle: Roman chamomile, geranium, lavender, copaiba, myrrh, frankincense or melaleuca(commonly known as tea tree). The Animal Desk Reference says that these oils can reduce itching and aid skin conditions. Mixing a supplement containing MSM, Omega 3 fatty acids, adaptogens, and antihistamines into your horse's feed may also help with allergies and skin conditions.
Doing everything in your power to prevent insect bites on your allergic horse is the best course of action. Spray insect repellent on him, dress him a fly sheet and fly mask when he goes out to the pasture, a maybe even turn him out when there are less insects out.
Airborne allergens include pollen, dust, mold, and other allergens found in the environment. A horse allergic to such allergens may suffer from either itchy skin and/or other skin problems, or respiratory problems that may include coughing, labored breathing, and a nasal drainage. for the skin conditions, use the same as I mentioned before. Mixing a supplement containing MSM, Omega 3 fatty acids, adaptogens, and antihistamines into your horse's feed may also help with allergies and skin conditions.
It is impossible to eliminate all environmental allergens, but trying to reduce them as best as you can can be helpful. If your horse is allergic to dust and mold, try to keep him outside where the air is fresh, and make sure his hay is clean and free of dust and mold before feeding it to him. Horses allergic to pollen benefit from staying inside when there is a lot of pollen in the air.
Horses can also become allergic to fly sprays, grooming products, or certain materials found in saddle pads, boots, and wraps. Lesions often appear on or near the area where the allergen was applied, making it a bit easier to find out where the allergen was found(lesions on the back may suggest the saddle pad, for example). Once you know that, find out the materials/ingredients and try to figure out what could have caused the reaction. Your vet may be able to help. Then, it can be as simple as not using a pad with that material or a grooming product with that ingredient. When using a new product, test it on a patch of skin first, then check back the next day to see if there is any reaction. If so, find a different product. If not, you may continue using it.
Some horses are unlucky enough to be allergic to common foods, such as grass and grain, both of which are usually fed to horses. Reactions include hives and itchy skin. If your horse is allergic to a certain type of food, it should be removed from his diet. Remember to read the labels of feed to make sure it doesn't contain that food. As I have said before, MSM, Omega 3 fatty acids, adaptogens, and antihistamines may be helpful in strengthening the immune system and reducing itching.
Having a horse with allergies can be difficult, especially if he is allergic to many things of something commonly found in the environment or in horse products. Talk with your vet if your horse has allergies. He or she may be able to help you with it.
PS: Someone I know urgently needs to rehome a chestnut Quarter Horse gelding. If you know someone who would be interested, please let me know as he needs to go to the auction April 6th. Heres the link: