Sell him at the sale barn and pass a probably contagious sickness on to someone else's herd or herds???

I would have the vet out to take a look at him and give a first hand opinion that it is either curable or put him down and stop spreading whatever it is. Don't pass it on to someone else.  The sale barn I use requires a statement on incoming cattle health and they look them over pretty carefully, as they should. jmho.

Jim at Dawn