My little pup is just now getting to the enthusiasm level I want to see. I am noticing he likes to chew on the bumper while carrying it back. Having just fought a hard mouth dog issue i am worried. Is this something I should let go and fix when I train hold or is it something you think could worsenand get hard to break. I dont want to squelch any drive at this point... not quite 6 months but as I said just starting to get retrieve crazy.