When my puppy had kennel cough, my vet strongly discouraged my from using any kind of cough medication. Sometimes, kennel cough can turn into pneumonia, and it can be a productive cough....you dont want to stop your dog from coughing nasty stuff out of its lungs.

Sometimes, it can lead to secondary issues like conjunctivitis, and like I mentioned, pneumonia, which is not pretty at all. If your dog is coughing up blood droplets, I hope you were able to make it a vet appointment ASAP, because I have never heard of that with kennel cough before, and probably means it's somewhat severe.

The problem with the bordatella vaccine is that there are SO many different bacteria that cause kennel cough, that it's impossible for the vaccine to protect against all of them. Antibiotics can help it go away faster, and prevent secondary infection, but every dog that I have known with kennel cough has taken weeks to clear up.

Good luck!!