If your dog is exhibiting any symptoms of kennel cough, take them to vet immediately and it’s generally recommended that you keep them away from other dogs, including in daycare and boarding, for at least 14 days. This is how long it takes for a dog to completely shed the virus from their system and no longer be contagious to other dogs. However, if your dog is completely symptom-free and has been on antibiotics for 3 full days, your dog can come back.