How does your son do with other animals? Is he gentle? We have 4 dogs, and my son learned early on to be gentle with them, not to play with their food or water, and to only touch them with his hands-- not sit on them, lean on them, etc.
Puppies are often rambunctious and nippy-- it's hard to train both a puppy and a toddler who aren't used to each other. On the other hand, puppies often form easy bonds with their children, and getting them to like each other is easier.
Older dogs are more predictable since their personalities are established, and you can get a better sense of whether they will tolerate children. Certain breeds are better than others. The downside is that they are set in their ways-- if it doesn't work out, it really doesn't work out.
Talk with your vet about what breeds would be best for your family, and find a puppy socialization class in your area.
at 12:29 AM on Mar. 20, 2011