What's the best age for child to have a pet?

A pet isn't a toy, so don't get it on a whim! I have a 3 year old boy and a 5 year old dog. There are days my boy gets along fabulously well with my dog - there are times my boy just doesn't want the dog around. But as dogs are man's best friend - my dog never gets offended. 😝 My boy grew up with a dog in the house so he is pretty much an animal lover and no fear of animals, which I am thankful for. He walks my dog too - it's really amazing to see their daily interaction.