Don't know about dogs, but don't cats feed themselves? Mine certainly does, when we leave for holidays (or even sometimes during the year) we just leave a lot of food and it just eats what it needs everyday.
In fact when I bought the recipient for holding the food (a kind of plastic vase with a hole at the bottom) there were a lot for sale at the shop so there must be many cats who can use that without harming themselves...
But leaving more than enough food lying around to be eaten ad libitum is a recipe for a fat cat, as they will not stop when they've had enough.
A dog would eat until it weighed 500 lbs, but some cats will actually pace themselves.
Possibly including the mice and rats attacted by all that food? let alone flies.