It does not matter if you happen to have cats or dogs running around your house because both of them, as well as any other pet basically has the same needs. They need to be fed, cleaned, taken to the vet, given attention and stimulated, and most importantly, given a proper place to stay. A lot of pet owners, especially new pet owners make the mistake of not buying a pet bed, and that is a really bad decision for a number of reasons.
Pet beds basically provide your pet a place to actually sleep in, and while they can sleep on the floor, the couch, your bed or some other part of the house, it is not actually comfortable for a lot of them. Older cats and dogs, as well as larger dogs tend to develop joint problems, and it can be really uncomfortable and painful for them to sleep on most surfaces. Having a proper pet bed gives their body the necessary cushion it needs and does not add any extra weight to their joints or extremities, giving them the right type of support they need, and allowing them to be able to rest comfortably. You can buy a pet mattress now and save on your Brentwood home mattress as well.
If you have a pet that is used to sleeping on the sofa or your bed and you are looking to make them stop doing that, you need to provide them with an alternative. No pet will willingly sleep on the floor if they are used to cushions and beds, so, by providing them with a comfortable pet mattress, they will have another option, and they will overtime warm up to the bed and then voluntarily stay away from the couch and bed.