Stress

According to CatChannel.com, psychological disturbance is a common cause of self-inflicted hair loss in cats. Cats under stress will often pull or chew their fur, even if their skin does not itch. Anxiety triggers in cats include changes in their environment and physical disturbance.

External Parasites

When cats are plagued by fleas, ticks and mites, they are often in horrible discomfort. Cats often will groom the infected areas such as the hind legs and the tail base by licking it repeatedly or pulling out fur. Check for bald patches, as they can be a sign that a blood-sucking parasite is lurking on your pet.

Urinary Discomfort

Cats can become infected with urinary tract infection, crystals, or a condition called interstitial cystitis. PetAlive.com notes that a common sign of a urinary disorder includes excessive grooming of genitals.

Skin Allergies

According to Pawprints and Purrs Inc., the most common way a cat deals with its feline allergies is by scratching at the skin. If the itching is localized, the fur in the concentrated area can become damaged or fall out.

Warning

If there is a change in your cat's grooming behavior, it is best to seek the advice of a veterinarian instead of ignoring it. Take note of your cat's behavioral changes, when it occurred and any possible symptoms of infection.

Source:

Cat Grooming

Symptoms of urinary tract infection in cats

Feline Allergies