By Eleanor Blazer
I glanced at the pastured horses on my way to the barn. I stopped when I came to Sport. He had hives…small swollen bumps on his neck and chest. They were various sizes, with the largest about the size of a nickel.
He had been fine the night before.
Sport wasn’t in any distress, but the victim of an allergic reaction to something which was resulting in the hives.
Hives, also known as urticaria, is the body’s reaction to the presence of high levels of histamine in the blood. Histamine helps the body fight allergies or foreign invaders like germs and non-beneficial bacteria. Unfortunately the side effects of high levels of histamine can be hives, nasal congestion and itchy, watery eyes.
Determining the cause of hives can be difficult. There are instances when something will come to mind – a change of feed, new fly spray, medication, new bedding or the presence of biting insects.
In Sport’s case nothing had changed. He was in the same pasture, eating the same feed, he had not been off the ranch and the bugs were not any worse than usual. His fly spray was not new and he hadn’t been treated with any medications.
Luckily Sport was not showing any signs of discomfort. He wasn’t scratching or in pain.
This is not always the case.
Many horses that contract hives also have skin irritation. They will rub themselves raw to get relief from the itching. In some instances horses may have fevers, lose their appetite or become restless or dull.
Not being in distress we decided to just watch Sport for the next several days. Many times hives clear up without intervention.
Sport’s owner arrived and rinsed him off with cool water. It was possible something in the air triggered the allergic response.
For horses having discomfort due to hives the veterinarian can prescribe an antihistamine. Antihistamines block or reduce histamine – reducing the side effects.
By late afternoon Sport’s hives were gone – never to return.
What caused them? We have no clue. It’s a mystery - another strange thing to be documented in our life with horses.