By Dr. Caity Cosentino

You drag yourself out of bed and down to the barn in the morning to feed your horses breakfast. One of your horses is standing quietly and is not interested in coming over for their morning feed. You find this unusual as they are usually more than happy to eat theirs and everyone else’s rations. Because your veterinarian has taught you well, you go grab the thermometer and take his temperature. It reads 102.8 F. Remembering that your horse’s temperature should not be above 101.5 F, you pick up the phone to call your veterinarian for advice.

Horses who develop a fever are often first identified by the fact that they lose their appetite. They are often a bit dull and stand with their head hanging. It is recommended to have the horse examined by a veterinarian to hopefully be able to identify the cause of the fever. Fevers can be produced by inflammation, infection, immune mediated causes or overheating. In a true fever, and not one in where the horse became overheated by work or lack of sweating, pyrogens in the body are responsible for raising the core body temperature. These proteins are produced by the body itself as a defense, or by the circulating bacteria/viruses that may be present. The body’s thermostat is told to maintain the new higher temperature as a new normal. This can be a double edged sword. The fever itself can in a way be protective, limiting the replication and survival of the invaders, but also causes a decrease in food and water intake and will cause weakness and muscle wasting in the process. If the fever becomes too high it can trigger seizures, especially in young foals.

Your veterinarian comes and does a full exam of your horse. He is in stable condition and his exam is overall good. His lungs sound clear, he’s had normal manure and he appears to be well hydrated at this time. So now what? You may be faced with a frustrating case of fever of unknown origin. Don’t get discouraged yet though, likely your veterinarian will want to run blood work. A complete blood count and serum chemistry can help shed some light about what is possibly going on. The other thing that is often consider in this area of the country are tick borne fevers. Sending out blood work to test for Lyme disease is prudent, especially if several days of high fevers have occurred.

At the end of the day, you may never know why your horse has developed the fever he has. Your veterinarian will help you treat him symptomatically. Non-steroidal anti inflammatory drugs, such as banamine, are often used to control fevers and provide relief. Horses are often put on a course of antibiotics to protect against infection as well as to treat a possible infection that is undetected. Gastric protection may be recommended until they are back to eating normally again. You will be instructed to check your horse’s temperature at least twice a day, before giving them the banamine. His food and water intake will be closely monitored while waiting for lab work results. Hosing him with cool water can help as well in between doses of medication. Most horses respond well to the conventional treatments for fever. Horses who are not able to maintain a normal temperature even with the conventional therapies may require more aggressive fluid therapy to keep them cool. These horses often have a more serious underlying cause of their fever.

It is important to know your horse’s normal’s. Normal temperature, normal heart rate, normal behavior and appetite. If you are familiar with your horses’ normal’s you will be able to detect any abnormalities early. Early treatment is often key to successful treatment.