Tim,
We recently got a new puppy too. She doesn't chew on my fletching but she was chewing on her kennel a lot. Our vet recommended bitter apple spray. We were able to find it at Petsmart and Petco. I am sure you can find it at any pet store. I am not sure if it would mess up your feathers or not but you might try it....or just spray it on the nock and shaft of the arrow. Or maybe use an arrow she has already chewed on and it will train her not to chew on the others. Just an idea I thought I would throw out there for you. Hope it helps.
Jon