Have your puppy vaccinated against Coronavirus at 9 - 12 weeks of age. Adult dogs do not require yearly boosters.
Proper Diet & Low-Street Environment
Be sure the puppy is free from intestinal worms and receiving a quality diet. Coronavirus takes advantage of weakened puppies, so anything you do to give it a low stress-high quality environment will help protect it from Coronavirus as well.
Avoid Contamination Contact
Avoid dog-to-dog contact or contact with objects that are contaminated with the virus. Do not take your new puppy to places that other dogs visit until its puppy shot series is completed.
Crowding, dirty facilities, grouping large numbers of dogs, and all types of stress make outbreaks of this disease more likely. Enteric Coronavirus are moderately resistant to heat, acids, and disinfectants but not nearly so much as Parvovirus.
The disease is a big problem in large puppy mills where sanitation and husbandry are poor. Most cases are brought to me by owners of puppies that were acquired at these breeders or in pet stores selling the puppies. These outbreaks could have been prevented by quarantining newly-arrived puppies and sanitizing the facility with a 1:20 dilution of ordinary household bleach.