Here are nine facts you need to know about fever in horses.
The normal temperature for an adult horse is 37,0 – 38,2 degrees Celsius.
Light fever starts at: 38,5 degrees Celsius.
High Fever: starts at 39,5 degrees Celsius
Life threatening fever: starts at 41 degrees Celsius
Very young foals have higher temperatures. 39 degrees Celsius is considered normal for a week old foal.
“Fever is not a disease, but rather a symptom that indicates a disease”, says Dr. Ines Kretschmer of the animal clinic Karthaus in Dülmen, Germany. “It is a defense mechanism. The heightened body temperature will have an effect on pathogens, bacteria, viruses or parasites.”
You need to be alert, when the temperature is too high. “Proteins in the body could be damaged and denatured”, says Dr. Ines Kretschmer. Without proteins, nothing functions in the body. They fulfill various tasks, such as transporting and storing oxygen in the blood, delivering nutrients, steering metabolic processes, and keeping the immune system in tact. “If it gets too hot, the proteins will fall out of their physiological form and can no longer fulfill their tasks. This is dangerous for the organism”.
Every living being has their own normal temperature. However, fever is the same for all: 41 degrees Celsius. The horse has a high body temperature and reaches the critical limit sooner than humans. However, 42 degrees Celsius is the absolute limit. It does not get higher than that.
The body temperature is regulated in the brain, more specifically in the Hypothalamus, a part of the cerebrum. “This part of the brain is set to a nominal value, which is the normal body temperature. Certain substances, the pyrogenes, increase this nominal value, which results in fever,” says Dr. Ines Kretschmer.
Exogenous pyrogenes are pathogens that enter the body from the external environment, such as viruses, parasites, and bacteria. These activate the endogenous Pyrogenes that are active inside the body and alarm the brain to heat the body.
You can usually detect a fever through the eyes of the horse. Often times they just stand apathetically in their box, don’t eat and are sweaty. “If the fever goes up to 41 degrees Celsius, horses can have orientation disturbances,” explains Kretchmer. Horses with light fever have a less obvious change in their behavior. The best way to check is to use a digital thermometer. If the horse is exhausted or stressed it can influence the measurement results. You should find a quiet, shady place where the horse can stand relaxed. After riding or when the horse has been standing in the sun, you should wait at least one hour before measuring the body temperature.
High fever, or light fever that lasts more than two days is a case for the vet. Once the vet arrives he has to find the cause. “The diagnosis needs to be done first,” says Dr. Ines Kretschmer. There are various causes for fever, such as bacteria, viruses, parasites or fungus. Influenza, Herpes or strangles are diseases that have fever as a symptom, sometimes together with coughing, swollen lymph nodes and nasal discharge.
Pneumonia, inflammations in the intestine area, tumors, poisoning, allergic reactions, heat stroke exhaustion and exhaustion can also cause fever. Treatment follows according to the cause.
“Just let them rest,” suggests Dr. Kretschmer. “ A horse with 39 degrees Celsius fever and not eating can be taken out to graze. However, when the fever reaches 40 degrees Celsius, a stroll out of the box should not be done. What you can do is take the horse out to cool off the legs with a hose and then take him or her back to the box.”
Fever is exhausting. Dr. Dr. Ines Kretschmer explains how to get your buddy back in shape. “Roughage is most important. You can also use plant oils, or beet pulp, which are easily digested and give lots of energy. But only, if the horse start to move again. You should not feed more than before. Horses often lose weight quickly and slowly build it back up. It’s better to take your time than to overfeed your loved one”.