Lazy employees.

You can run the vet clinic yourself. I used the cheat code to get mine to 10. So he can create all the treats, and put them in the vending machine to sell. He can also exam the pets, and perform surgeries. Although the surgery is just the pet going inside the surgery machine, and then choosing one of three procedures. It is funny sometimes when the pet comes out looking like a lawn ornament, or grass sculptor though. Of course it is sent back in to "get it right" I will have to try the locked door thing. I notice the customers go into the owner's office from time to time. Will have to lock that for household. I have also added a shower, refrigerator, dishwasher, and counter space so I can take care of my sims' needs should I keep them there the full 8 hours. And there are plenty of sofas to sleep on. I always buy the electric vacuum cleaner (looks like an iRobot Roomba) that comes with the Cats & Dogs expansion, to automatically clean up, but it only has two settings, every 12 hours or 24. I can of course tell it to start cleaning anytime I am there.