“Walking the dog! Walking the dog! If you don’t know how to do it, I’ll show you how to walk the dog.” This is a song lyric that I have always taken literally – because, truth to tell, I’ve never known how to walk the dog. I want to leave the dog lying on the floor, after all, is there any creature in creation more deliciously reposeful than a slumbering hound. But no: the dog must be walked; this clever species, which has parasitised on humans now for thirty-odd thousand years, understands how to rouse us up, force us to clip ourselves on to their lead, and then let them lead us about cheerless suburbia for an hour or two. How pleasing it is to think that as soon as civilisation crumbles, dogs will be out together again, the Borzoi and the Poodle, reunited in a quest for carrion.