My Cat Is Scratching … What Gives?

By Jennifer Coates, DVM on May 4, 2016

Cats suffer from many different skin diseases that make them itchy, and the nearly incessant scratching that results is enough to drive owners crazy! Everybody is miserable when cats are so itchy they can’t stop clawing or biting at themselves. But don’t despair. While there are many causes of scratching in cats, and it can be difficult to tell them apart, all of the following common itchy skin diseases are treatable.

Fleas

Flea allergy dermatitis is the most common cause of itching in cats. Triggered by a hypersensitivity reaction to proteins in the saliva of fleas, and that saliva from a bite will start the itch-scratch cycle. Identifying fleas or flea “dirt” (flea feces made from your cat’s digested blood) makes the diagnosis straightforward. However, some cats are such efficient groomers it can be next to impossible to find fleas or flea dirt on their skin. In these cases, response to regular use of good a flea control product can help with the diagnosis.

Treatment and prevention centers on the use of an effective flea control product such as an oral or topical medication. It is vital to treat all pets in the house for several months or more to get rid of all life-stages of the flea. Thoroughly vacuuming the house, washing pet bedding in hot water, and treating your home and yard may speed up the removal process.

Lice and Mites

Other external parasites like lice and mites can also cause itching in cats. Lice attach to the hair shaft and are seen by closely examining the hairs. Mites live on or just under the surface of the skin, and usually can be identified when a veterinarian examines skin tests under a microscope. Ear mites can cause intense itching around the ears, head, and neck. These mites are easily seen under the microscope, and can also sometimes be identified by placing a clump of discharge from the ears on a black background. If you see tiny white “bugs” moving around, those are the ear mites.

Medications that kill the specific parasite affecting your cat, used according to label directions, are usually quite effective.

Environmental Allergies

Cats with inhalant allergies (atopy) tend to be young and initially develop itching in the spring and/or fall. As time goes on, symptoms often get worse and may occur throughout the year. Some cats may have concurrent sneezing or other respiratory symptoms. Since itching may occur anywhere on the body, atopy can be difficult to differentiate from other itchy skin diseases in cats. Evaluating the patient’s history, symptoms, ruling out other conditions, and confirming a response to treatment are often necessary to reach a definitive diagnosis.

Food Allergies

Common food allergens in cats are beef, fish, and dairy products. Less commonly, wheat, corn, chicken, and eggs are to blame. Food allergies do not necessarily occur only after a diet change. Your cat may have been eating the same food for years before developing an allergy to it.

Cats with food allergies often scratch their face, neck, and ears, but other parts of the body may also be affected. Occasionally, digestive signs such as vomiting, diarrhea or a decreased appetite will also be present. Food allergies can only be diagnosed with a veterinarian prescribed food trial to see if the itchiness resolves. A prescription diet is best because over-the-counter foods often contain trace allergens. All other treats and flavored medications must also be withheld during this time.

Ringworm

Dermatophytosis (ringworm) is a fungal infection that may cause hair loss, itching, and crusty skin lesions. To diagnose ringworm, your veterinarian will pluck some hairs from your cat, place them specialized jar or container, and monitor for growth of infectious fungal colonies. Treatment for ringworm can include dips, or an oral an oral prescription medication. Environmental decontamination using as directed by your veterinarian is important to limit the spread of the infection to other pets and people.