The pup has been playing with the young cats a lot. They tussle and have great fun. Pup has started to race by them and bump them with her shoulder to try to get them off their feet. She tried it this morning with old dog, who is very short but long and stocky (picture a shepherd/rottie on stumps, weighing about 60 pounds). Pup bounced off old dog's shoulder and went rolling down the deck steps. She popped back up looking very perplexed.