We have used this style of dog bed "Kuranda" (
Kuranda Dog Beds - Patented Orthopedic and Chewproof Dog Beds ) in our kennel for decades. They work very well for our herd of Great Danes.
Our Danes had literally ate hundreds of 'pillow' style beds and bed covers before we found these "chew proof" dog beds.
They are a bit expensive, but they last forever, are easy to clean and the dogs love them.