A normal, temperature for an adult horse is 98.0 — 102.5 degrees Fahrenheit. High-grade fevers and low-grade fevers are managed differently. A temperature over 105 degrees Fahrenheit is considered a high grade fever and needs immediate medical attention. A low grade fever may not warrant an emergency visit but should at least elicit a medical phone consult. It is important to note your horse’s attitude and demeanor, appetite, drinking, manure output, and urine output. Also, are there other horses on the property that are having problems with a fever? If so, do you know the diagnosis or suspected diagnosis? The answers to these questions can be helpful information that can help your veterinarian assist you.