When your dog lies down, the heaviest parts of the body press into the bed. For large dogs, those pressure points are usually the hips, shoulders, elbows, and spine.
If the bed is too thin, your dog may “bottom out,” meaning the foam compresses so much that the dog feels the floor underneath. This can make the bed less comfortable and less supportive.
A thicker orthopedic dog bed gives the foam more depth to absorb pressure and support the body.