Tempurpedic

What an interesting piece for your hairy pals! This pet mattress is made of double covers — the inner sides are liquid proof, so that it protects the mattress foam throughly; the top cover is soft and very comfortable. It also comes with removable and washable covers, for easy cleaning.

For a little under $60, your pets will definitely delight in resting on this.

via Ikea

Older pets need the care and support the most. Perhaps it would be great to get them one of these:

The Buddy Bed!

Keeps memory foam clean and dry.
It is Anti-Bacterial
It is Anti-Microbial
It is Anti-Dust Mite
It is Hypoallergenic

via Buddy Bed

A made to order mattress for your pets, the Woof-A-Pedic is developed using the same technology as other memory foam mattresses. Combined with pocket coils, this pet mattress gives comfort and ample support and is covered in waterproof but breathable material called microvelvets.

10 Year Guarantee — Pocket Coil deformity.
5 Year Guarantee — Natural Response fiber constructions

Available Sizes:
Small 27″ x 21″, 6″ H, for dogs 10-25 lbs.
Medium 30″ x 27″, 6″ H, for dogs 25-80 lbs.
Large 44″ x 32″, 6″ H, for dogs 80-120 lbs.

Shipping in the USA only.

Pet owners most often think that a pet mattress or cushion is enough to serve as a pet bed. But there are undoubtedly some cats or dogs who do not prefer these and instead sleep on the master’s bed. Pets also look for comfort in their sleeping space (and you think this only applies to humans, huh?) and one way to achieve this is to set a pet’s bed up with a good pet bed frame.

As with any typical bed frame, you can just easily put the mattress on top and have a special bed for your dog or cat instantly. But like shopping for your own bed, you have to choose the bed frame conscientiously.

It is easy to regard this as a fairly simple looking pet mattress. But behind its simplicity, this item offers something extra special — it is made of 100% Mongolian cashmere. It’s something that should last you very long, as you cannot simply throw cashmere away. Care is via dry-cleaning. The standard price is $399 and it is available at Friends of Cashmere.

If you have an old sweater you don’t use anymore, you can still make use of it by turning it into a warm and cozy mattress for your dog or cat.

To make your own pet mattress you will need:

A large old sweater, preferably 100% wool (found cheaply at the thrift stores)
polyester or cotton batting or old rags for stuffing
yarn
tapestry needle
scissors

WikiHow shows you how to do it in a step by step guide.