We have an 8 year old greyhound. I was looking for an orthopedic type bed and was not finding anything that would work for him. I bought the Casper dog bed after we humans bought a mattress. Best money I’ve spent on Xander. The sides of the dog mattress are forgiving but also raised - they hold up to a head laying on them or Xander curling up against them. It’s the perfect size for either a total splay or a curl-up and he definitely likes the options the sides provide. We couldn’t be happier with it.