It's a trend that's been developing for some time, which is memory foam beds as the best dog beds for pets who have arthritis or creaky joints, or who are just getting older and less limber. You've heard of memory foam beds for humans, in which polyurethane cells in the mattresses mold themselves to the sleeper's body and return to their original shape when the person gets up. These beds provide support like no other mattress, so they've been recommended for humans with spine or joint problems. There's no reason why dog bed furniture of memory foam can't do the same for pets.
The best dog beds for joint problems like this should provide a cushion that reduces pressure, to relieve the pain of the joints themselves and the accompanying muscles. Memory foam gives that sort of support. This is especially good for larger dogs, because many are prone to hip dysplasia, a degenerative joint disease where hip joints don't always fit properly and the muscles near the rump are weak. Large dog beds made of memory foam can relieve aggravation of the affected limbs when the dog lies down, or ease sore muscles on dogs that have worked hard during the day.
Some people supply heated beds for their pets with joint problems, however it's probable that memory foam is similarly advantageous. One benefit of memory foam is its breathability. This means that it holds in warmth throughout the cold seasons, but is cooler during the summer when overheating might otherwise be a problem.
The extra winter warmth of memory foam is what may make it the best material for a dog affected by arthritis, because not only will it preserve the animal's body heat when it's required, but it also can provide a shield against ground temperatures that may become slightly too cold during the night.
Keep in mind that even if these small memory foam mattresses are the best dog beds when it comes to support and comfort, you'd still have to guard against an over enthusiastic chewer. You'd need a sturdy cover to put over the mattress to keep the dog from chewing on the polyurethane. But memory foam can help provide excellent orthopedic dog beds for older dogs or those with arthritis or other joint problems. It might be worth going that extra mile if it can help your dog sleep more comfortably.