If two dogs are slipped together and they dont make any mistakes i.e. one trips and joins in again few seconds later! It would be ok... But in reality thoses things happen and dogs end up running different courses altho they are chasing same thing and thats when it gets risky! Lamping is a risky buissness anyway and in my view running two dogs together makes it even riskier, my dog was on a chase this season when lamping and a mates dog slipped its lead and joined in and had a collision with my dog, two dogs lucky and escaped but could have been different story the speed they traveling. In my