2 days ago I noticed that he had a thick, light yellow string of mucus coming from one nostril. Not pouring out, just kind of sitting there. I wiped it away and didn't see it again until last night when we rode him. Some more discharge came out, and he was coughing a little (2 or 3 times). Today one nostril looks a little crusty and there is still some discharge. The vet will be out tomorrow to see him, but I was hoping to get some input because I'm nervous.
He isn't acting sick AT ALL. No lethargy, no loss of appetite. No personality change at all. His vacs are up to date, including strangles.
There WERE 2 rescue horses who came onto the property afew days before he left the trainer, who both had runny noses. But they were being kept totally isolated from the other horses (in another building), no one was allowed to touch them except the barn owner, and she was disinfecting herself with lysol after handing them. After a week on antibiotics, both of those horses are doing well.
I don't really have a good way to isolate him from our other 2 horses (they were all turned out together for days after he came home anyway), an 11 year old paint gelding and a 24 year old pony. Neither of them show any signs of any nasal discharge/cough at all.
Any input appreciated!