"If it's kennel cough it'll go away within a week as long as you stay away from cough meds and Antibiotics . "
Or give them cough meds along with Antibiotics , and the dog recovers faster. Mine recovered in 48 hrs on Baytril plus Robutussin. My previous adult dog about 24-36 hrs after starting Antibiotics . Adult dogs can recover on their own in a 1-2 week time frame. Puppies can easily develop life threatening cases of pneumonia due to secondary bacterial infections.
The original post of watery eyes and cough does not sound like Kennel Cough, which produces copious amounts of nasal mucus and congestion.