
Hi.
Has his voice changed? does it seem more high pitched or squeaky?
It could be Laryngeal paralasys, Labs do get it. I think if he has had anti-biotics and anti-inflammatory drugs, and his chest and lungs are ok, it stands a fair chance. It will need to be confirmed by a specialist, you will need to be referred by your vet , they will confirm it. Surgery is successful, they tie back the vocal cords, because they are collapsing and suffercating the dog. I may be wrong, but I would investigate that avenue if I were you. Keep us informed and good luck.
Dawn.