Hamburger to a dog and tuna salad to a cat really isn't so bad, minus the condiments and bun that's what they eat naturally only raw. I don't think wild dogs eat kibbles and bits nor do wild fish eat NLS. That being said prepared foods are typically better for the animal with all the added vitamins and such but it can't be looked to down on to supplement with the odd treat provided your not feeding your
fish kibbles lol.
I feed my racing greyhounds raw meat mixed with barley, meal, brown sugar, and a few other things with vitamins and some peaches sometimes. They are some of the healthiest dogs you'll see running 1/3 of a mile in 30 seconds