If you already have healthy dogs, it can be important when adding a new puppy to the mix that the newest addition be kept away from your other dogs to be sure he's not a sick puppy. Isolating the new baby for a short time can prevent the potential spread of illness to your other pets. New puppies should see a vet for an exam and necessary treatments such as puppy shots before or shortly after adoption.
Why Quarantining a Puppy Matters
Some puppies may be sick and contagious without showing symptoms right away. The incubation period—the amount of time from exposure to development of symptoms—varies depending on the disease. For instance, the incubation period for canine parvovirus is five to 11 days, while rabies can be months or even years. Even dogs that recover from distemper can infect other dogs for 90 days after they're well. But in most cases, puppies incubating a contagious disease become sick within two to three weeks of exposure.
If you aren’t sure about your new puppy’s health—perhaps he’s a stray you found—quarantine him for at least two weeks. A month is better to reduce the risk of exposure to your other pets.
If the baby stays healthy he can be safely introduced to your home and other pets.
How to Quarantine
You’ll want to segregate the new pup in a “safe room” anyway as preparation for introductions. Choose an easily cleaned area such as the laundry room or an enclosed porch. Try to ensure the quarantine area is well ventilated.
Make sure the new arrival has all the necessary puppy paraphernalia including food and water dishes, toys, and a bed. The new pup and your resident pets should have no direct contact, not even sniffing through the screen or beneath the door, as even this risks disease transmission.
Use a disinfectant to keep the quarantine area and canine necessities clean. A good all-purpose disinfectant is bleach at a dilution of one cup bleach to two gallons of water. Remember to also disinfect yourself following interaction with the new dog, particularly after cleaning up any accidental puddles or piles. Sick puppies often can't control their elimination and shouldn't be expected to abide by house training until well.
Wear an oversize shirt and sweatpants or other “puppy-only” uniform like a smock or apron while interacting with the quarantined baby. When you leave, take off the special smocks and thoroughly clean your hands before making contact with the other pets. Don’t forget to wipe down your shoes to prevent carrying something nasty out of the room. Get a shallow pan and fill with a small amount the disinfectant, and step into the liquid with your shoes after you leave, so that you kill any bugs that could infect your other pets.