The worst can food is likely better than the best dry food. Owners should not regularly feed their dog or cat dry food. By far the best diet for dogs and cats is a homemade raw one. There are plenty of quality recipes online. If one chooses to feed a can diet a way to greatly upgrade the quality of the diet is to add ingredients like raw vegetables, ground flax seeds, ground sunflower seeds, lecithin granules, and very lightly cooked eggs(just enough to kill any harmful bacteria). Vegetables can be chopped fine in a food processor and a nut grinder or coffee grinder will grind the seeds into meal in seconds. Missing Link makes a quality supplement with natural ingredients, but it's much cheaper to make your own.
The homemade recipe I use for my cats costs about 50 cents per cat per day. Smiths in Las Vegas almost always has boneless chicken thighs for $1.99/lb. Liver, gizzards, and hearts are even cheaper.
Cat and dog homeade recipes have different requirements. Cats are obligate carnivores and need probably 70-80% of their diet to come from meat. Dogs can get by with much less meat and most veterinarians even consider them eligible for veganism.
