The Country Pet Waterproof Crate & Kennel Mat would be a great addition for your dog
Not only is it a comfy place for your dog to sit it also has an anti-slip base
The surface can be wipe clean for a light clean or if really dirty it can be hosed down
Small size 60x40cm
Medium size 70x50cm
Large size 80x60cm
XLarge 100 x 80cm