My older dogs having a hard time getting up from laying down?

It really sounds like arthritis. You need to have a soft, thick dog bed or cushion for him to lay on. While lying on the hard floor, his body is getting sore and stiff from the arthritis. You can give him a baby aspirin (NO Tylenol - it is toxic to dogs) to help with the pain. You could also put a long runner/rug down for him to walk on so he doesn't slip.