I have seen those photos where the dogs don't get their bigger beds because the cats take it and then the dog is stuck with the cat's smaller beds. This happens at our house, too. Only, we have more than one doggy bed and more than one kitty bed. 

Here is Mystique in the doggy bed. It was empty and she didn't chase any dogs away. The next photo shows you why she is in their bed. (and the bedding needs washed now that the snow is melting.)

Here is Jedi on the cat's mat. It is too small for him and he is using it as a pillow. The dogs, with all their fluffy fur, get hot and the pillows in their beds makes them even hotter. They find the flat kitty mats cooler and more to their liking. 

So don't feel sorry for the dogs, they had two more beds in the room that they were ignoring.