Hello Yuukie,
seeing that I managed to Menagerie kitties by mistake and hitting the wrong buttons in the past already I'm pretty highly against permapetting by kitty-menu-button. Also I do think that the menu as it is now is already very considerably and it will sure grow even more bigger anyways...
No, I personally like the real feeling of "going shopping" in SL and that includes going to grab food, vitamins and permapet pills for my little furball-babies. It's the least I can do for them.
