As little as 20 years ago it was still common to feed a dog on only table scraps. Because of modern veterinary knowledge and production methods this is no longer seen as healthy for your dog. In fact, meat sold in supermarkets has already been trimmed and de-boned and is ready to be cooked right out of the package with no additional preparation. The advent of frozen food has put an end to vegetable trimmings, and all of our dairy and poultry comes from cartons and cardboard, not directly from the animals themselves. We live in a world where all of our food is pre-prepared and pre-packaged for our convenience, table scraps are nearly unheard of.
When a meal is prepared from all these cookie-cutter packages, there is almost no extra food for our little furry friends. The only things left are usually inedible or tiny amounts. Certainly nothing that would satisfy a hungry dog. These tiny unwanted quantities of food will not suffice as a proper diet for a dog.
Before a dog owner feeds his dog scraps off the kitchen table he should ask himself a question. What would he do with that additional food if he didn't have a dog to feed it to? Would he put those leftovers in the refrigerator and save them for his next meal? If so, then it's absolutely fine to give the scraps to his dog. On the other hand, if he knows that he would never eat those scraps and would probably throw them out, then he is simply using his dog as a trash can.
And this is not the only reason that table scraps are unhealthy for dogs. Despite the fact that a dog will gain no nutrition from table scraps he will certainly enjoy the taste. Sometimes table scraps are used to make a nutritionally balanced, commercial dog food more appealing to the dog. Unless these scraps have been chopped into very tiny pieces and are well blended with the the dog food the dog will only ignore the dog food and pick out the scraps.
Table scraps mostly contain empty calories. They are filled with fats and carbohydrates, with little of the proteins, fiber, and vitamins that all dogs need. The great danger is when a dog becomes so accustomed to table scraps that he loses his appetite for the much healthier regular dog food. It simply tastes too bland to him now. A dog owner may feel that he is treating his dog to a great injustice by refusing to feed him table scraps. He feels that he isn't giving his dog what it wants. In the long term scheme of things, the dog may refuse his food at first, but eventually he will become hungry enough to eat. The owner may feel like he is starving his dog, but he is doing it with the best possible intentions: a happy healthy companion.