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Thank you for your advice. My son wants to take a puppy from a shelter, and I decided to read up on what we need to buy for him at first.

Congrats on this fantastic decision. We got our dog from the shelter, too, and I think it's still grateful for that. For the puppy, I suggest you buy the same food they feed the dog at the shelter, so it doesn't get an upset stomach because of the sudden change in food. Of the other supplies, get a dog bed to teach sleeping on its own place, a leash and harness set for walks, and diapers until the puppy gets used to going to the bathroom outside. You will also need bowls, puppy shampoo. Be sure to check with your veterinarian at https://chouchou to determine when your baby needs to be treated for parasites and given age-appropriate vaccinations.