You have to love dogs. Unlike their rather cynical feline foes, their enthusiasm knows no bounds.
A bowl of food, a new toy, their master or mistress returning home from work - all are greeted with the same infectious ecstasy.
In Tyson the boxer's case, it's being told he is going for a walk that gets him going. So much so, it makes him spring like a salmon during spawning.
Have you ever seen a more excited reaction to 'walkies' in your life? Well, if you have a dog, you probably have.