There is no black-and-white answer to how long kennel cough is contagious, writes Debra M. Eldredge, DVM. She advises pet owners to keep the dog out of his activities for a week after the last cough. Kennel cough, now called CRDC, can be caused by various bacteria and viruses.
Kennel cough is highly contagious and can be spread via droplets, dog-to-dog and coughs that mist on blankets, dishes, and toys. One sick dog can potentially infect an entire kennel, shelter, or daycare. Even vaccinated dogs are likely to get ill if exposed to an infectious dog, but symptoms tend to be milder, and recovery is faster.
Source: Whole Dog Journal, October 9, 2024. Link.