He may, for instance, go into a classroom with a child's painted cereal bowl. Maybe it will be one child's favourite dish. "Because you love your dog, you'd let him eat out of it, wouldn't you?" "Ugh... no way."
"Is that because of the things that dogs do with their mouths? Because they don't have toothbrushes, mouthwash.
"But how many of you let them lick you with a tongue that comes from the same mouth?" The penny drops. Message: personal hygiene.
Or he'll arrive with a cardboard pet carrier. The children think there's a puppy inside and are surprised when a soft toy is revealed. Then the discussion starts about the difference between a cuddly toy and a puppy. Real puppies cost money, need food, need shelter; a cuddly toy doesn't need anything. Message: responsibility.
Or he'll move on to non-verbal communication and "talking Dog" instead of English. "What is a dog telling you when he's lying on his back with his feet in the air?" "That he wants his tummy rubbed." Not quite. It means he's surrendering. Not a bad one to get wrong; more dangerous if a child misinterprets the body language of an angry animal. Message: personal safety.
He's even been known to give a geography lesson. "We talk about the places certain dogs come from - like pekinese or labradors. Or we'll talk about why some dogs have short coats, while others have small bodies and shaggy coats, others have big feet. It's a bit of biology, a bit of geography, a bit about movement. But really it's that we're all valuable wherever we come from; whatever we look like."