My grandson just turned 3. He learned quickly when he comes into the kitchen, where the dogs always are, to walk around the kitchen facing the counters, with his back to the dogs, towards my kitchen bar chair. He climbs up in it and watches the dogs and they can lay their heads in his lap for him to pet. When we first got Max, he was 5 months old and Mason, my grandson, was only 1.5. He was knocked down quite a bit, accidently, and it took us a while to teach Max not to paw him in the face. That is when he learned to walk with his back to them, by the counters. If they brush up against him, he can brace himself on the counters. He grew up with 2 hyper pit mixes and a chi, so he is very dog savy. As long as you watch your grandson, with the dogs, he should be just fine.
Kathy