Why does my dog chew the pads on her paw?

i don't know!!! it's weird though ! i know that dogs in their first and second year they can chew anything in front of them beacause their teeth start coming out! but chewing their pads ! i don't know i've never heard that...it could be an allergie though...in my opinion you should take her to a vet and for now try to put something that tastes bad on her pads so she doesn't do that !