Your cat spends large amounts of time during the day grooming himself. These sessions involve alternating periods of licking, chewing and pulling on his hair to make sure it's squeaky clean. Sometimes this attention to hygiene can move past what's normal and cause excessive hair loss.
Parasites
Most parents, at one point or another, will announce that the behavior of their children makes them want to pull their hair out. While cats don't necessarily share this exact sentiment, the presence and antics of other small creatures do have a similar effect on your pet. The bites of fleas and skin mites can irritate your cat's skin, causing intensive itching and spurring them to groom excessively to try and relieve the discomfort.
Skin Infections
Things don't need to crawl on your cat's skin to make him want to groom himself bald, as fungal skin infections can have the same effect. A common skin infection your cat might experience is ringworm, which is a fungal infection that can actually pass from your cat to you. This condition has additional symptoms, such as scaly, irritated skin. Your veterinarian will perform a number of tests, including blood work and skin scrapings, to correctly diagnose ringworm.
Psychological Issues
Some cats don't yank their hair out in response to physical stimuli, but to emotional ones. Cats have the animal equivalent of obsessive-compulsive disorder -- they like routine and can find new situations and sudden changes stressful. Grooming helps ease stress, so they end up grooming more often in times of stress and change. Depending on the situation, this could cause your cat to over-groom, resulting in pulling his own hair out in his attempts to calm himself.
Treatment
Stopping your cat from plucking himself bald requires the discovery of the source issue. Most retail stores sell flea medications, but only your veterinarian can diagnose mites or other health issues and offer the proper treatment. Psychological issues are a little more difficult to diagnose, as you can't exactly ask your cat what's bothering him. Think back to when the behavior first started and whether there was an obvious change in routine. A new food, new pet or change in household can all trigger excessive grooming. Calm enhancing products such as synthetic cat pheromones help ease stress and encourage relaxation, and some extra one-on-one time with your pet might help soothe his nerves.
References
Writer Bio
Jane Williams began her writing career in 2000 as the writer and editor of a nationwide marketing company. Her articles have appeared on various websites. Williams briefly attended college for a degree in administration before embarking on her writing career.