Food and Nutrition
The most important thing you can do for your dog is to feed them the best food you can find, that is natural, and as close to organic food as possible. This means you are looking for a premium protein source. Beef, chicken, turkey, lamb, duck or fish that is not a by-product or a secondary protein source. Think of it this way, you are eating the chicken breast and not the chicken feathers. Most protein for pet food is from the processes carcass of the animal, and ground into a filler for production. There is very little nutrition in this process.
Looking at the ingredient list is the key. If you are reading this list, and you are not finding much that you can understand, you are wise to move on to a list that you know, and one that will be easily understood.
It is true, there may be some natural preservatives in most good dog foods, and they will be explained as such. They may add some minerals and some flavorings, and all should be noted as a natural addition. You should try to switch your best friend over to this new food slowly, as the transition can be sometimes very upsetting to any dog's digestion.