I need help with healthy dog food?

Purina Puppy Chow is a good food. I am not familiar with Cesar food. The best foods are going to come from your vet. You should avoid any generic food. Jack Russells are high energy dogs and he/she may need a higher quality of food to ensure optimal growth. When you take him for a check up be sure and ask for your vets opinion. You could probably just put a call in to your vet for that answer. Most will gladly give you their opinion without having you come in for an appointment. I only feed Purina and have had dogs that reached 13years and 20 years!! I would think that a good indicator of good quality food!