Hi, depending on the size of your dogs, (labrador?) or a bit smaller, you might need a single bed size mattress. Hope you find what you need, and the dogs have a comfortable sleep. How old is the oldest dog, just wondered as Pedigree Joint Care chews worked well for my old dog, and eased the stiffness, and he was 15yrs old. The chews are made for three sizes of dog, small, medium, and large. 7 days chews in one box, one chew per day. There's a picture of the dogs on the box which shows the size of dog they are meant for. You might like to try them.