Some time has passed since the pet was added to the game. My pets grew and they missed eating. Therefore, it seems to me that it would be good to introduce the function of turning useless pets into useful foods.
How is that little white dove going to eat all that though?
Once your pet reaches Mythical, you can exchange spare pets for food of that pets color on a 1 for 1 basis…
Pets will not resort to cannibalism until you’ve boosted their metabolism via the not-ascension mechanic. A mythic pet is so crazed by your lust for power it abandons its inhibitions against eating its own kind.