I dont understand why people are asking Vets about Dog Nutrition !?! Vets are Generalist Doctors for animals. Since when do doctors know anything about Nutrition that anyone else knows about, they are not Nutritionist or Dietisians.
Vets for animals = Doctors for humans.
They teach as much about nutrition in Vet university than to Doctors in University, which is very little.
Vets are not Nutritionist !! stop asking them for advice.