When the Body Attacks – The Horse

ADVERTISEMENT The immune system is charged with protecting animals from external pathogenic, or disease-causing, threats such as bacteria, viruses, fungi, and parasites. But sometimes it gets a little carried away, sending its defenders out on missions to destroy things a bit more benign. Allergies develop when the immune system responds to contact with outside “foreign” proteins, called allergens, that wouldn’t normally harm the animal. These include dust particles and components of insect saliva, pollens, and other plant and animal proteins. In horses, allergic responses most commonly arise in the skin and respiratory systems. Basics of the Battle Several key immune system players are involved in allergic reactions: