Dog enters ruck?

[Robert Goodman]

This came to me in a dream last night. Sports and games frequently figure in my dreams, about as often as difficulties in traveling do.

The safety hazard caused by a small dog or cat crawling under a ruck is one thing, but how would you rule in a situation where a large dog enters a ruck or maul? Suppose its hind feet are onside, and as far as you can tell it's binding legally with at least one front paw. You'd want to continue play, wouldn't you? And just assume the dog to be a player you hadn't noticed previously. If one side is wearing solid colors, "all-furry" should be easy enough to assign to that side.