Most puppies are interested in babies because they have so many interesting smells: milk, baby food, poop… what’s not to love? Confident and well-socialized adult dogs can be tolerant of toddlers as long as they acknowledge that they have not yet grown up.
However, many puppies and adult dogs are inexperienced with infants or toddlers, who may become frightened if they follow your pet, tug at its tail, and/or make strange shrill sounds. Babies who crawl can imitate prey behavior in their sounds and actions. Cautious dogs may switch to play mode or take a defensive stance, trying to ward off the “scary” creature by growling and showing teeth. Neither option is the perfect start to a positive experience for both dog and child.
Children are also lower to the ground, at puppy level, where all of his most prized possessions are at risk. Your new baby knows nothing better than playing with dog toys, climbing into a puppy crib, and/or exploring a food bowl. It’s natural for dogs to be protective of their belongings, and they may react with aggression if a child doesn’t understand a puppy’s warning growl or other body language.