OK, so I can't picture the collar chewing unless it's really so lose around her neck that it hangs down. So my question on the leash is,why don't you pull it out of her mouth right away when starts to chew it?
It is not loose. I have a basenji and she loves to chew. She bends her head down and chews. I also have been known to not have my eyes on her at moments, so that is when she chews her leash. We take her everywhere with us, but "us" includes my 4 and 6 year old, so I am also keeping my eyes on them. I did not ask this question for any reason other than a suggestion, not criticism. If I thought the answer was pull it out of her mouth then the problem would be solved. If Halo chews her leash for less than 1 minute, it is on it's way to being split into 2 pieces.