chewing on feet occasionally

Question
I have a 7 year old female Brittany Spaniel. I've noticed her chewing on her back feet and front feet/wrists in the past. She recently started doing it again. I'm assuming her feet are bothering her, I feel like she's in pain maybe its arthritis? She runs around and stuff like usual, she's very happy and playful but she is getting old. Maybe it's allergies so her feet itch? Her vet gave me cortisoothe shampoo a few years ago for allergy in her skin but it's expired now. Is that something I should purchase again? I want her to be as healthy and happy as possible so if she's in pain I want to help her. I will be taking her to the vet sometime in May.

Answer
As you suggested, it could be pain, but more likely allergies.  It could also just be nerves.  I am NOT a vet and do not have any formal medical training.  I think your idea to buy some soothing shampoo is good (oatmeal based is good for itching) and consult with your vet.  Your vet will probably ask you if you've changed anything lately like the dog's food or shampoo or the detergent you wash the dog's bed with.  She could be allergic to any of those changed things.  It's also possible for a dog to develop food allergies, even to foods that they've been on for years.  Good luck and do consult your vet.