Pro Plan sensitive is a good food and often recommended by veterinarians.
Zignature is a quality kibble, grain free, potato free. My dogs do well on the Whitefish (lowest sodium content of all the Zignatures) I would add a splash of water and a bite of real food.
Natural Balance is loaded with potato and sweet potato which doesn’t agree with some dogs that have sensitive stomachs, hard to digest.
Glucosamine chondroitin is a supplement and may not be necessary
Go here for science based veterinary medicine
http://skeptvet.com/Blog/?s=glucosamine
http://skeptvet.com/Blog/category/herbs-and-supplements/
