Yes, this explanation didn't help him identify dogs as living.

I asked him our neighbor's dog was alive and he said no - but I blame that on my neighbors not celebrating their pet's birthdays...those monsters!

Nothing stops anyone from celebrating a stray (or neighboring) dog's birthday. The difference between a dog and a chair in that context is the dog will wag its tail in an expression of happiness if given a birthday treat. The chair won't. So being able to experience happiness may be an indicator of life. Just watch some young squirrels running and jumping over each other this Spring. That's life.