What kind of things do you give him to chew on?
I had a couple of teething toys that I put in the freezer for them but I don't recall what they were called. (I think one was by "Stages" and the other by "Chillee".)
Also, I gave mine some "all natural" chews by Merrick.
Sometimes you just need to do the bait and switch.
At 14 weeks old your puppy will likely continue to chase after your 3 yr old. Puppies are learning - like your toddler - it will take time.
Good Luck!
__________________  Connie |