Id possibly take the rest to the vet as IF he had a RI, and it was that developed in the same rack, they may have it aswell. You could do anything from
F-10 + Fogger, to the shots that you give every 3 days. Would hate to see them hide their developed RI's. (If you haven't of course) But the f-10 + Fogging could be a good precaution, Without introducing Antibiotics.