At Lucky Dog, we try to be proactive by recommending your dog get the H3N2 and H3N8 canine influenza vaccine.
Here is some information from the American Veterinary Medical Association:
The symptoms are cough, runny nose, and fever, but not all dogs will show signs of illness.
It is spread to other dogs by direct contact with aerosolized respiratory secretions (coughing and sneezing) from infected dogs. This can happen in any environment where dogs are in close proximity to each other (i.e. dog training facilities, grooming salons, pet stores, dog parks, and of corse: daycare and boarding establishments).
If your dog is coughing, contact your vet, keep them at home, and avoid contact with other dogs. Please talk to your vet about getting your dog vaccinated.