My 3 hens appear to have tapeworm, they are doing the neck wrenching and yawning type of thing and we've had. I eggs for 6 weeks. They originally looked poorly and I thought it might be a copy type problem but having read up on tapeworm I thing that's the problem. At the moment other than no eggs and the neck wrenching thing they appear in perfect health. Yet after a full 7 day course of flubs vet they still seem to have gape worm. My hens are in a permanent coop and so I change their flooring regularly and in fact just 2 weeks ago and we have stopped giving them food on their coop floor. Any advice ?