Veterinarians have wryly observed that months can go by without seeing a
particular disorder in their veterinary practice, and then suddenly: three
in a row. It’s uncanny. I experienced this phenomenon on a recent Saturday
in my own New York City cat practice, where our clinic was transformed into
the set of a new daytime soap opera: The Bald and the Beautiful.
Figaro, Poousch, and Decaf - three cats with balding bellies and hairless
Feline skin disorders are a diagnostic challenge. While there are many
distinct feline skin disorders, they all may present with similar clinical
signs, although certain “reaction patterns” are more common in some
disorders compared to others. Examples of some common reaction patterns
seen in feline dermatology are hair loss (alopecia) and small widespread
scabs and crusts (miliary dermatitis).
Baldness may be okay for Sphynx cats, Chinese crested dogs, and Seinfeld’s
George Costanza. For many cats, however, it may be a sign of allergy,
parasites, or infection. Quite often, a psychological disorder is
triggering the hair loss.
Hair loss in cats should be investigated by a veterinarian, where careful
questioning and examination will determine whether the hair is falling out,
or if the cat is chewing the hair or yanking it out through over-grooming.
Clients may actually report to the vet that the cat is grooming herself
excessively, and that hairballs have become increasingly difficult to
control. Finding broken hairs during the exam confirms that the cat is
chewing at its fur. Successful treatment will depend on the cause of the
Allergies are a common reason why cats over-groom and pull out their fur.
Flea allergy, food allergy, and atopy (allergy to airborne substances) are
three common causes of allergy in cats. Flea allergy is suspected if fleas
or flea dirt is noted during the exam. Even if fleas are absent, flea
allergy can be involved. Fleas deposit their saliva into a cats skin before
they draw their blood meal, and flea-allergic cats may show a severe
reaction to the saliva, even from one flea bite. The itching can be
intense, and cats may lick and chew excessively at their skin, especially
around the base of their tail.
Adverse reactions to food may manifest themselves via the skin. Severe
generalized itching, small scabs and crusts throughout the haircoat (called
“miliary dermatitis”), itching around the head, neck, ears and face, and
self-inflicted hair loss due to over-grooming may be seen. Blood tests and
intradermal skin tests are available, however, these are generally
considered unreliable for the diagnosis of food allergy. Dietary
elimination trials, in which the cat is fed a diet containing a protein
source they haven’t encountered before (such as duck, rabbit, or venison)
are necessary to obtain a definitive diagnosis. These trials require
patience on the part of the owner, as it may take anywhere from 3 to 8 weeks
before improvement is noted.
Allergies to airborne substances (called “atopy”) such as pollens or dust
can lead to itching and subsequent excessive grooming and hair loss.
Miliary dermatitis is another common manifestation of atopy. Achieving a
diagnosis can be tricky. Clinical signs that are seasonal are suggestive of
atopy, although signs can be seen all year round as well. Blood tests can
be performed to see if the cat is allergic to plants indigenous to a
particular geographic region as well as to common household dusts and mites,
although some dermatologists still feel the blood tests to be unreliable.
Intradermal skin testing, in which tiny amounts of allergenic substances are
injected into the skin and the skin reaction noted, is a more meaningful
diagnostic test. This should be performed by an experienced veterinary
dermatologist, however, as the skin response to the injections can be subtle
and more difficult to interpret in cats. Specific treatment of an allergy
is possible if the allergen(s) can be identified and avoided or removed from
the environment. Often, this is not practical, especially in patients
allergic to airborne pollens. Hyposensitization – serial injections of
progressively larger amounts of the offending allergen – is probably the
most appropriate long-term control method for cats with a prolonged allergy
season. Other therapies that can be considered are anti-histamines, omega-3
fatty acids, and corticosteroids. Although steroids have the potential to
have side effects, the doses necessary to control allergic dermatitis are
unlikely to cause problems, especially in cats, as cats are more resistant
to the undesirable side effects of steroids as compared to dogs.
Ringworm is a skin fungus that may cause hair loss. It is the most common
infectious skin disease in cats. Any age, sex, or breed of cat may be
affected, although young cats, older cats, and longhaired cats are more
frequently affected. The fungus invades the hair shafts, and hair loss
results. Some cats with ringworm infection are very itchy, while others
don’t seem to be bothered by it. Most cats develop scaling, crusting, and
redness at the sites of infection. Some cats will over-groom and develop
hair loss. Ringworm infection should be considered in any cat with
symmetrical hair loss. Ringworm is a “zoonotic” disease - it can be
transmitted to humans. When clients present their cat with a classic
circular crusty skin rash, and they themselves have a similar rash, you can
be almost certain that ringworm is the culprit. A definitive diagnosis,
however, is achieved through fungal culture. Treatment options vary,
depending on the situation (an individual cat vs. cattery or multiple cat
household, longhaired cats vs. shorthaired cats), but may involve some
combination of clipping the coat, topical therapy (usually shampooing), oral
medication, and environmental decontamination. Treatment is often
successful if clients are diligent about following the prescribed protocols.
Once parasites, allergies, and other medical problems have been ruled out,
psychogenic alopecia – hair chewing and overgrooming due to psychological
factors such as stress, fear, anxiety, or nervousness - must be considered.
Cats are very sensitive to their environments, and a move to a new home,
addition or subtraction of new people or animals to the household, or any
other unexpected change to their surroundings can provoke grooming behavior
that is excessive, leading to hair loss. Grooming is a comfort behavior,
often used by cats to relax themselves. It shouldn’t be surprising that in
the face of stress or anxiety, they may turn to excessive grooming to dispel
their anxiety. Cats of Asian lineage (Siamese, Abyssinians, Burmese and
Himalayans) are apparently more susceptible to psychogenic alopecia,
presumably because of their high-strung, nervous temperaments.
After a thorough medical exam and diagnostic testing, all three cats that
came in to my practice that Saturday – Figaro, Poousch, and Decaf – were
eventually diagnosed with psychogenic alopecia. Figaro’s case was the most
clear cut. His hair loss began as soon as Ernie (another cat) was added to
the household. All three cats had licked the fur off their abdomens and
inside their thighs. Figaro’s over-grooming had progressed to his tail,
while Poousch and Decaf were also chewing the hair off their forearms.
Ideally, the treatment of psychogenic alopecia would involve the elimination
of the potential stressors in the cat’s environment. Unfortunately, this is
often impossible, and anti-anxiety or anti-depressant medications are often
warranted to control the problem. “Psychogenic alopecia is a diagnosis of
exclusion”, says Dr. Heather Peikes, a board-certified veterinary
dermatologist who practices in New York City. “When all of the common
causes of hair loss have been ruled out, I will prescribe a drug such as
amitriptyline or doxepin. Behavior modification is also an important part
of the treatment plan.”
Feline dermatology has become a discipline in its own right, and a
systematic approach to feline skin problems is necessary to define the
underlying cause so that appropriate management can be instituted.
Sidebar: Finding a veterinary dermatologist
Veterinarians are general practitioners, trained to be proficient in most
aspects of veterinary medicine and surgery. Cat owners who want more
specialized care may seek out a veterinarian who specializes in cats.
Sometimes, however, it may be necessary to consult with a veterinarian that
specializes in a body system rather than one that specializes in a species.
“Specializing in one body system allows a dermatologist to recognize
clinical signs and disorders that a general practitioner may not, and to
keep abreast of novel treatment options”, explains Dr. Heather Peikes, a
board-certified veterinary dermatologist at Animal Allergy & Dermatology
PLLC, in New York City. Clients whose cats require this kind of expertise
should expect their veterinarian to be able to refer them to a qualified
veterinary dermatologist. “If your veterinarian cannot refer you, you can
visit the website of the American College of Veterinary Dermatology at
www.ACVD.org to find a nearby specialist”, says Dr. Peikes.
Some feline skin disorders occur as a result of a disorder in an unrelated
body system, and a veterinary dermatologist may not be the only specialist
to consult when dealing with skin disorders in cats. “There are
veterinarians who specialize in feline behavior, certified by the American
College of Veterinary Behaviorists, who can also be helpful in treating
cases of psychogenic alopecia”, says Dr. Peikes.