[anonymous]

Stop listening to strangers on the internet and people that work at pet supply stores that may or may not have medical training/expertise.
Take your dog back to the vet for a quick exam and go by his recommendations.
You may find this site helpful: http://skeptvet.com/Blog/2016/07/more-nonsense-from-holistic-vets-about-commercial-therapeutic-diets/

This is not veterinary advise; consult your veterinarian.