Details for Diagnosing and Treating a Runny Nose and Cough in a Yearling Paint Horse

Purchased a yearling paint horse today and he has a runny nose. Since we got him unloaded and settled, he has a slight cough. I will be getting him to the vet as soon as possible. I was wondering if anyone has any idea what this could be. He seems otherwise healthy. We got him some electrolytes and put it in his feed. Eating and drinking just fine. The lady we got him from purchased him from auction about 10 days ago and he didn’t get along with her stud pony so she sold him to us. He had been on pasture only with some hay, but somewhat confined due to the pony not getting along with him. We have him on pasture, and feed. Coggins negative, and his paperwork shows he had no known illness at auction.