Expert Answer: The BabyCenter Editorial Team
Many babies become interested in patting dogs when they're as young as 6 months old. That's fine, as long as your dog is comfortable with the attention and you keep a close eye on your baby at all times. Never leave your child alone with a dog, even if it's your well-trained, easygoing family pet. You never know what could make a dog snap. Older dogs are often less tolerant of young children, and puppies can be unpredictable.
Your child won't be ready for real "play," such as throwing a ball, giving commands, or chasing, until he or she is much older. Teach your child good doggie-play manners as soon as he or she starts showing an interest in dogs. That means no pulling ears or tails, hitting, or teasing – and leaving dogs alone when they're eating, sleeping, feeling ill, or chewing on a bone or toy.
If a dog is loose in your neighborhood or at the park, don't let your child go near it. And never approach a dog that's tied up, even if you know the dog and it seems friendly, unless the owner is there and you can ask permission.
Some parents worry that dogs will pass germs to their babies when they lick or slobber on them. It's true that dogs' mouths can harbor bacteria, especially if they've been chewing on unsanitary things. However, germs tend to be species-specific, meaning dog germs are unlikely to make your child sick. Some experts even think that exposure to dogs – and dog slobber – can help kids avoid asthma and allergies later in life
by challenging their immune systems. So while you probably don't want your dog "kissing" your baby on a regular basis, a few licks here and there are nothing to worry about.