First and foremost, cats are independent creatures. If we could ask them why they do certain things they might reply, “Because I can.” In the same sense, cats have a unique feel for their own cleanliness. Cat’s often live for years by self-cleaning – licking their paws and wiping various parts of their bodies. This also helps the cat get some of the external bacteria (from its coat) into its body, through the mouth.
Cats generally don’t need baths. Many don’t react well to the idea of being bathed, for good reason. Too much washing can actually take away helpful bacteria and oils that are part of the cat’s protective layer. One theory is that cats roll in the dirt outside or even in the dust under a bed as a way to get some of these needed bacteria back on their coat.
Some people believe that a cat rolling in the dirt is trying to tell us that it doesn’t need to be washed anymore. It’s supposedly trying to put back some of those needed bacteria. If a cat isn’t washed regularly it still is trying to replace these bacteria (even if it isn’t trying to send a message).
If you see your cat rolling in the dirt quite often and you have developed the habit of bathing the cat regularly, you should reduce the number of water-and-shampoo baths. Excessive combing and other types of grooming may also cause problems for the cat. Cats can generally maintain a perfectly healthy coat without a lot of help from the outside. If you reduce the number of baths for your cat you should see the pet rolling in the dirt less than before.
Cats may also like the feel of rolling on the ground, even the feeling of the dirt. If you feel there may be a problem with the cat’s skin or coat you should visit your veterinarian. Describe the cat’s actions in detail and the vet should be able to find anything that might be causing serious problems.
There may well be another part to this. Cats may roll in the dust in a shady area outside or under a bed during hot weather because it is trying to cool itself. Animals have to get rid of body heat in a different way than human beings, primarily because their bodies are covered by fur. They don’t dissipate as much heat as we do because of this fur-covering. In fact, dogs and cats rely on getting excess heat out of their bodies by using their open mouths. This is especially true of dogs.
Finally, your pet is much more sensitive to smells than you are. The cat may be rolling in dirt or on the floor to get some particular odor on its coat. While it is tempting to care for your cat as much as you can, doing too much can actually cause harm. The cat usually knows best.