My 13 year old Paint started running a fever 8 days ago. The only symptoms are the fever, lethargy, and reduced appetite. He is still eating, mostly hay, and is mostly uninterested in his grain. The Vet came out last Tuesday and put him on one antibiotic, and then Monday, took him off that one and put him on 3 more. Lungs are clear, and blood work came back normal white blood cells and only slightly low red blood cell count. No coughing, no nasal discharge. He is sound, no bites or wounds anywhere, and my Vet is baffled. There is a virus going around the barns in the area with the same symptoms but it was only lasting 4 to 5 days. Fever has been as high as 104, but is usually around 102, but seems to be lower in the evenings. Sunday he did not have much of a fever and was not on bute or banamine. Treating with those only when fever goes up. Any ideas? Could it just be the virus taking a little longer than average? If it is bacterial, where is it coming from. Thursday will make it 72 hours for the new antibiotics, and if he is still running the fever I will transport him to the equine clinic for further testing. I am worried sick. Also-9 other horses in the barn, he is turned out usually with the gelding herd, and no one else is sick.