Ideally for proper portioning and access control within a home each cat and/or dog in a house would be given its own feeder and tag. The PortionPro Rx portions out food for a single pet and any pet being fed normally can still be stolen from by other pets in the home. There are some circumstances when you could purchase less feeders than you have pets. An example is if you have a dog that steals food from the cat and you want to stop that behavior. Purchase a feeder for the cat and an additional tag to put on the dog. The cat can eat freely and the dog will be restricted from accessing the food in the bowl.