Bethany, I don't know that a particular type of dog bed is designed just for pit bulls. But here's what I do know...
Most owners would like to find the perfect dog bed for their pet. Usually, this means that the perfect dog bed will be sturdy, washable, and comfortable. Most dog bedding deceives pet owners by saying the dog bed is washable when in fact, the cover is washable and the pillow is not. So it is important to find a dog bed in which both the pillow and the case can be washed if the need arises. Both of the two types of bedding are great choices that fulfill all of these perfect bedding qualifications.
Luxury bedding is bedding that is of higher quality, comfort, and style. Luxury bedding can be found online or in brick and mortar stores. Luxury bedding may be heated, orthopedic, or contained in furniture. Heated bedding is great for pet owners' dogs that remain outside during the winter. Orthopedic dog bedding is great for pets that need additional support for sore joints. One of the newest trends is the dog bed that is contained in furniture. This type of dog bed allows you to fold it back into the furniture as if it where never there. Luxury bedding offers pet owners additional options that they would not typically have if purchasing their pet's dog bed at Wal-Mart, Target, etc.
A new trend among pet owners is the dog filled air bed. This type of dog bedding has several advantages for both the pet owner and the pet. Some pet owners may have their pets outside in which they are exposed to fleas and ticks. Non-air filled dog bedding allows fleas and ticks plenty of space to hide while the air bed does not. The dog filled air bed also limits allergens for pet owners as the cover is easy to wash and allergens can not go any deeper than the cover. Aside from its cleanliness, the dog filled air bed is also transportable. If you are traveling out of town or even to the lake, you can rest assure that your dog will be able to rest in comfort as this bed is deflatable.
Hope this helps you make an informed decision.