Feline Allergies: Why is my cat grooming so much?

What are allergies, and how do they affect cats?

One of the most common reasons that a cat may seem itchy, twitchy or groom excessively is allergies.  In the allergic state, the cat's immune system "overreacts" to foreign substances (allergens or antigens) to which it is exposed.  Those overreactions are manifested in three ways.  The most common is itching of the skin, either localized (one area) or generalized (all over the cat).  Another manifestation involves the respiratory system and may result in coughing, sneezing, and/or wheezing.  Sometimes, there may be an associated nasal or ocular (eye) discharge.  The third manifestation involves the digestive system, resulting in vomiting or diarrhea.

Severe skin allergies are easy to recognize - some cats develop bare spots on their sides, legs, or abdomen where they lick and chew at their fur. Other cats may develop severe sores or wounds where they cause trauma to themselves. However, it can be hard to recognize the signs of a mild allergy. These cats may twitch their skin or become irritated when petted, or they may lick or chew at the air or nearby objects when they are scratched at the base of the tail. These are itchy cats, even if no one ever observes them grooming excessively.

 If you search "cat licking air" on YouTube, you will find videos of hundreds of itchy cats.

Skin allergies can take a long time to resolve, even when they are not this severe

 
In some cats, the itchiness eventually becomes so bad that in addition to wounding themselves, the cats develop a secondary bacterial skin infection. This little 2 year old presented to us for a second opinion after 6 months of treatment elsewhere. She was treated with steroids and antibiotics, and after another 5 months, she was doing really well. Now she is maintained on periodic low doses of steroids to prevent this problem from becoming so severe in the future.

Aren't there several types of allergies?

There are four known types of allergies in the cat: contact, flea, food, and inhalant.  Each of these has some common expressions in cats, and each has some unique features.

Contact Allergy

Contact allergies are the least common of the four types of allergies.  They result in a local reaction on the skin. Examples of contact allergy include reactions to flea collars or to types of bedding, such as wool.  If the cat is allergic to those, there will be skin irritation and itching at the points of contact.  Removal of the contact irritant solves the problem.  However, identifying the allergen can require some detective work.

 Flea Allergy

Typical flea allergy scabs on the back of a cat's neck

Flea allergy is common in cats.  A normal cat experiences only minor irritation in response to flea bites, often without any itching.  Many times when we find fleas on a cat, the people he lives with are surprised because the cat has not shown any sign of irritation  or discomfort. The flea allergic cat, on the other hand, has a severe, itch-producing reaction when the flea's saliva is deposited in the skin.  Just one bite causes such intense itching that the cat may severely scratch or chew itself, leading to the removal of large amounts of hair.  There will often be open sores or scabs on the skin, allowing a secondary bacterial infection to begin.  The area most commonly involved is over the rump (just in front of the tail).  In addition, the cat may have numerous, small scabs around the head and neck.  These scabs are called miliary lesions, a term which was coined because the scabs look like millet seeds. These areas are most commonly affected because they are the areas the cat has the most difficulty clearing of fleas.

The most important treatment for flea allergy is to get the cat away from all fleas.  Therefore, strict flea control is the backbone of successful treatment.  Unfortunately, this is not always possible in warm and humid climates, where a new population of fleas can hatch out every 14-21 days.  When strict flea control is not possible, injections of corticosteroids (or "cortisone" or "steroids") can be used to block the allergic reaction and give relief.  This is often a necessary part of dealing with flea allergies.  Fortunately, cats are more resistant to the side-effects of steroids than other species.  If a secondary bacterial infection occurs, appropriate antibiotics must be used.  

Sometimes, one cat in the home may have a severe flea reaction and another will seem completely unaffected. However, it is important to treat ALL animals in the household (dogs, too!) because otherwise, the fleas will continue to reproduce on the untreated pets in the home.

Inhalant Allergy

The most common type of allergy is the inhalant type, or atopy.  Cats may be allergic to all of the same inhaled allergens that affect us.  These include tree pollens (cedar, ash, oak, etc.), grass pollens (especially Bermuda), weed pollens (ragweed, etc.), molds, mildew, and the house dust mite.  Many of these allergies occur seasonally, such as ragweed, cedar, and grass pollens.  However, others are with us all the time, such as molds, mildew, and house dust mites.  When humans inhale these allergens, we express the allergy as a respiratory problem; it is sometimes called "hay fever."  The cat's reaction, however, usually produces severe, generalized itching.  In fact, the most common cause of itching in the cat is inhalant allergy.

Some cats rub their faces, others lick parts of torso or limbs

Most cats that have inhalant allergy react to several allergens.  If the number is small and they are the seasonal type, itching may last for just a few weeks at a time during one or two periods of the year.  If the number of allergens is large or they are they are present year-round, the cat may itch constantly. 

Treatment depends largely on the length of the cat's allergy season.  It involves two approaches.  Steroids will dramatically block the allergic reaction in most cases.  These may be given orally or by injection, depending on the circumstances.  As stated previously, the side effects of steroids are much less common in cats than in people.  If steroids are appropriate for your cat, you will be instructed in their proper use.

A medication called Atopica (cyclosporine) can be used to target and suppress the activity of certain cells (such as eosinophils and mast cells) in the immune system that are involved in inflammation. Inflammation is what causes the irritation and itching sensation due to allergies. Often this medication can be used to help reduce the dose of steroid that is required to treat the allergy, and in some cases, it can control the allergic reaction on its own.

Another useful treatment for allergies is a product called Dermoscent. This topical application is a synergistic blend of 10 essential oils that are rich in essential fatty acids and Vitamin E that has been shown to increase fur shine and decrease dandruff and hair loss. Similarly to Atopica, Dermoscent can help decrease the need for steroid use in allergic cats and can sometimes eventually become the sole treatment for the problem, eliminating the need for oral medications altogether. However, in most cats, steroid and/or cyclosporine treatment may be necessary initially to counter severe inflammation and give the Dermoscent time to work.

Some cats are helped considerably by a hypoallergenic shampoo.  It has been demonstrated that some allergens may be absorbed through the skin.  Frequent bathing is thought to reduce the amount of antigen exposure through this route.  In addition to removing surface antigen, bathing alone will provide some temporary relief from itching and may allow the use of a lower dose of steroids.  Antihistamines are usually of little value in the cat but can be tried. 

Allergy testing can be done intradermally or with a simple blood draw

The second major form of allergy treatment is desensitization with specific antigen injections (or "allergy shots").  Once the specific sources of allergy are identified, very small amounts of the antigen are injected weekly.  This is all in an attempt to reprogram the body's immune system.  It is hoped that as time passes, the immune system will become less reactive to the problem-causing allergens.  If desensitization appears to help the cat, injections will continue for several years.  For most cats, a realistic goal is for the itching to be significantly reduced in severity; in some cats, itching may completely resolve.  Generally, steroids are not used with this treatment protocol.  This therapeutic approach is recommended for the middle-aged or older cat that has year round itching caused by inhalant allergy.  This approach is not successful with food allergy.

Although desensitization is the ideal way to treat inhalant allergy, it does have some drawbacks and may not be the best choice in certain circumstances and for these reasons: 

1.        Cost: This is the most expensive form of treatment. 

2.        Age of Patient: Because many cats develop additional allergies as they get older, young cats may need to be retested 1-3 years later.

3.        Success Rate: About 50% of cats will have an excellent response.  About 25% get partial to good response.  About 25% get little or no response.  The same statistics are true for people undergoing desensitization.

4.        Food Allergies: Although tests for food allergy are available, the reliability of the test is so low that it is not recommended at this time.  A food trial remains the best diagnostic test for food allergy.

5.        Time of Response: The time until apparent response may be 2-5 months, or longer. 

6.        Interference from steroids: Cats must not receive oral steroids for 2 weeks or injectable steroids for 6 weeks prior to testing; these drugs will interfere with the test results.

Food Allergy

Allergic cats are usually affected by proteins sources like chicken and beef

Cats are not likely to be born with food allergies.  More commonly, they develop allergies to food products they have eaten for a long time.  The allergy most frequently develops in response to the protein component of the food; for example, beef, pork, chicken, or turkey.  Food allergy may produce any of the clinical signs previously discussed, including itching, digestive disorders, and respiratory distress.  We recommend testing for food allergy when the clinical signs have been present for several months, when the cat has a poor response to steroids, or when a very young cat itches without other apparent causes of allergy.  Testing is done with a special hypoallergenic diet.  Because it takes at least 8 weeks for all other food products to get out of the system, the cat must eat the special diet exclusively for 8-12 weeks (or more).  If positive response occurs, you will be instructed on how to proceed.  If the diet is not fed exclusively, it will not be a meaningful test.  We cannot overemphasize this.  If any type of table food, treats or vitamins are given, these must be discontinued during the testing period. 

Because cats that are being tested for inhalant allergy generally itch year round, a food allergy dietary test can be performed while the inhalant test and antigen preparation are occurring. 

Whatever the cause of your cat's allergy symptoms, for most cats, therapy of some kind will be required for the rest of their life. For some cats, the treatments may be given seasonally, but for most cats, the treatment must continue year-round, but at the lowest effective dose.

Can I buy a hypoallergenic cat?

Siberian Cats are advertised as hypoallergenic cats

Is there a hypoallergenic breed?

Dr. Bailey’s quick answer: There's no such thing.

The rest of Dr. Bailey's answer: The classic allergen, Fel d 1, was originally identified as a feline salivary allergen, so the hair served as a carrier of the allergen.  I am sure the "cat allergy" syndrome is far more complicated than we even understand currently.  For instance, Fel d 1 is pleomorphic (has many forms)!  It really depends on what individual people are allergic to - different allergic folks react differently to other cats. We have sent cat owners to the E.R. after they arrived at our practice (but they live with one or more cats at home!).  Is this simply dose related, or was it exposure to different allergens?   Some studies have shown that darker colored cats seem to cause more allergic signs than lighter colored cats. Calm cats are less likely to cause allergy issues than calm cats, and pregnant or nursing females or unaltered males are more allergenic than spayed and neutered cats. Other studies have shown that males are more allergenic than females, mean females cause less reactions than nice females. I guess you could tell an allergic friend to get a calm but mean, light-colored spayed female cat.

I am allergic to cats, but I take far more antihistamines now than I did 10 years ago; and when I started working with just cats (over 20 years ago) allergies were not an issue.  I did not have a cat as a child.  I guess I can blame my mother? (Children raised with cats tend to be less likely to suffer pet-related allergies.)


What is this Fel d 1?
Originally, it was thought that cat hair caused allergies, but as more research was done, it was discovered that a protein in the saliva called Fel d 1 is deposited on the cat's skin and coat when it grooms. The protein then enters the environment when the cat sheds hairs and skin flakes (dander). This protein is the major cause of most cat allergies.

More recently, it was discovered that there are at least EIGHT different proteins that cats produce that can cause allergy symptoms, and that they are not all located in the saliva. The major allergen, Fel d 1 is even found in many different forms in many places on (and in!) the cat.

Now for some veterinary technical-speak...
These are the known feline allergens:

Fel d 1 = Secretoglobin. This molecule is pleomorphic! This is the allergen culprit in 90% of cases. Fel d 1 is found primarily in the sebaceous gland in the skin, but also in small amounts in the salivary gland, male cat urine, and perianal glands.
Fel d 2 = Albumin
Fel d 3 = A cystatin
Fel d 4 = Lipocalin. Another major allergen, a urinary protein - This is the culprit in about 60% of allergies.
Fel d 5 = Oligosaccharide galactose-alpha-1,3-galactose (alpha-gal) on cat IgA (secreted in saliva)
Fel d 6w = Feline IgM also??
Fel d 7 = von Ebner gland protein isolated from the tongue (Can f 1 homologue)
Fel d 8 = Latherin-like protein isolated from the submandibular gland (homology to Equ c 5)

Most secondary cat allergies are caused by Fel d 2 (feline albumin) or Fel d 4 (feline lipocalin).  Serum albumin accounts for about the largest number of cross-reactions between cats and other animals.

About 25% of people who are allergic to horses also react to Fel d 4.  These individuals are considered horse/cat cross-reactive.

It is known that some cats and some breeds shed less Fel d 1 than others, but little to no research exists yet as to the levels of the other allergens (2-8) in these cats.

What if I discover I have a cat allergy, and I love cats - what can I do?

Cats tend to cause more allergy symptoms than dogs because their dander is sticky and light, and travels everywhere easily. If you have cat allergies, you can try having someone who isn’t allergic brush cats daily and then clean the brush thoroughly to minimize dander. You can also use a damp washcloth to wipe down cats regularly. It is important to note that vacuums with HEPA filters will help eliminate allergens in the environment, but regular vacuums will spread them. Ask your veterinarian about healthy diets for your pets to prevent dry skin and cut down on dander.

If you do what you can to minimize pet allergens, but still have symptoms of pet allergies, you may want to see an allergist. An allergy specialist can help you pinpoint what may be causing your allergies — it may be that your allergies are worse in the winter, not because you are cooped up indoors with your cat, but because you are allergic to environmental factors that are worse in the winter when all the doors and windows are shut (such as dust mites). Your doctor can then recommend treatments such as allergy shots or medication to help control your allergic reactions. Many times, if your allergy is complex, being able to manage some of the allergens will help you tolerate the others, so you may find as you treat your other allergies, you become more tolerant of your cat.

The jury is still out on whether kittens are less allergenic than adult cats. James Seltzer, MD, a spokesperson for the American College of Allergy, Asthma & Immunology says that in general, kittens shed more allergens than cats. Although the levels seem to drop at 6 to 12 months of age, "they still cause allergies," says Dr. Seltzer. This is due to the fact that kittens are growing and shedding their epidermal layer more rapidly. Others suggest that kittens are less allergenic because many of the proteins that cause allergies are related to pheromones and sexual maturity (remember - spayed and neutered cats are less allergenic) which kittens have in lower supply. Also, kittens are smaller. It is likely that adult and juvenile cats activate different allergies because of different protein levels. Your cat may "outgrow" your allergy or conversely a cat you have lived with for a while may begin to cause more problems as he grows older - just another important reason to spay and neuter your pets; it will help keep the allergen levels down!

Allergy shots or "hyposensitization therapy" can help people with cat allergies.

Dr. Seltzer says that allergy shots (desensitization therapy - routine injections of allergens in order to decrease allergic response) are more likely to be successful for those allergic to cats than those who are allergic to dogs. "Allergy shots for cat [allergen] can be effective in as many as 65% of people, but it does take a year or two often to start working."

 The good news? Research has shown that in most cases, people tend to become desensitized to the cats that live in their own home over time. They may be able to tolerate the one cat in their home but break out with runny eyes and sniffles when they bring their cat to the vet. Research has also shown that kids raised in homes with a pet tend to have fewer allergies, themselves. And children raised in homes with multiple pets tend to have a lower incidence of allergies than those with only one pet - 66-77% lower! In addition, preliminary research seems to shows that children raised in a home with pets tend to have fewer illnesses in the first years of their lives.These studies are exciting to animal lovers, but they really don't answer the question as to whether the cats and dogs are the CAUSE of the increased health, or whether people who own pets just live a healthier lifestyle - or at least a lifestyle that is more beneficial to the immune system.

But I know I have heard about hypoallergenic cats!

Patented hypoallergenic cats?

Studies suggest hypoallergenic cats and dogs can cause just as many symptoms as the regular kind, says Dr. Seltzer. Allerca is a company that launched in 2004 to produce pets free of the major allergens, Fel d 1 (cats) and Can f 1 (dogs). Prices for cats ranged from $6,950 to $26,950 and dogs are available for $15,950. They ceased breeding these animals in January 2010 - many suspect this is because the animals still were causing reactions in allergic individuals despite the high price tag and company claims.

"The problem is that removing these proteins from the skin, saliva, and other secretions may not be enough," says Dr. James Sublett, the vice chair of  Arlington Heights-based American Academy of Allergy, Asthma and Immunology’s Indoor Environments Committee. As noted above, animals produce other symptom-triggering allergens. "Both dogs and cats have what we call minor allergens, so it's not only the major allergens," he says. "Most people have a sensitivity to minor allergens too."

 Aren't there certain breeds that are less allergic?
Siberian cats are strongly recommended by many cat enthusiasts as a hypoallergenic breed."There are no scientifically validated studies to show that any particular breed of cat, whether it's Siberian or anything else, is quote 'hypoallergenic'," says Martin Chapman, PhD. He's the president of Indoor Biotechnologies, an allergy testing company that provides the kits for most of the world's studies on allergen exposure.

As can be seen in the information provided on this site, while the Fel d 1 protein in 2 Siberian cats exists in much lower numbers than in two other cats, there is still some protein present. This test of fur allergen levels is cited by many Siberian breeder websites as evidence the breed is hypoallergenic, However, many others criticize this study, since only 4 cats were included, all the samples were submitted by a Siberian breeder, and one mixed breed cat tested with allergen levels of over 60 times higher than the highest allergen level tested in cats anywhere else (62,813 micrograms). The fact remains that many people report that they are less sensitive to Siberian cats than the general population of cats at large. However, individuals with allergies to other animals (especially horses and rabbits), or food allergies to eggs and pork meat often react to low Fel d1 Siberians.

Siberian Cat: Triple Grand Champion, Karat

A not-for-profit association of breeders, (Siberian Research Inc), was founded in 2005 to study allergen levels and genetic diseases in the Siberian breed. As of March 2010, fur and saliva samples from over 300 Siberians have been submitted for analysis, many directly from a veterinarian. Salivary Fel d1 allergen levels in Siberians ranged from 0.08-27 mcg per ml of saliva, while fur levels ranged from 5-1300 mcg. The high-end of these ranges is consistent with results from prior studies, though the low end is below expected results. All Siberians tested were found to produce some Fel d1, with the highest levels being found in Siberians that have silver coloured fur. About 50% of the Siberians tested were found to have Fel d1 levels lower than other breeds, while under 20% would be considered "very low". Within the low group, males and females had comparable allergen levels.

Other breeds that are variously considered to be "hypoallergenic": Balinese, Bengal, Burmese, Colorpoint Shorthair, Cornish Rex, Devon Rex, Javanese, Ocicat, Oriental Shorthair Russian Blue, Siamese and Sphynx

Devon Rex

Some of these breeds have fewer hairs per follicle or even lack hair completely, which provides less surface area for allergens to cling to. Other breeds also have lower Fel d 1 proteins, like the Siberian cat. There is no guarantee that a hypoallergenic breed is going to be a cat that you can tolerate, if you have allergies.

While little research exists about allergen levels in other breeds, or about minor allergen presence in any breed, this information does seem to suggest that some people with allergies may find some breeds more tolerable versus other breeds. Definitely, this is an area that could use much more research so that cat lovers with allergies can enjoy feline friendship with the rest of us crazy cat people!

Further reading about hypoallergenic cat breeds:
Pet MD

Cats of Australia

Catster

Is my cat "hairy" or furry"?

Various cat coat colors and textures

What’s the difference between fur and hair? Is a pet with hair better for allergies than a pet with fur? These are the questions that sparked this article. Based on the amount of discussion about this topic, both here in the hospital and through email with friends, colleagues and family members, this year has been a particularly bad year for allergies, and people are looking to do whatever they can to feel better!

In 2001, Scientific American magazine interviewed Nancy Simons, a mammalogist at the American Museum of Natural History in New York about the difference between hair and fur. Her answer? There isn’t. Hair and fur are the same thing.

A cat hair (top) compared to several human hairs (bottom)

Really, hair versus fur is a matter of semantics – it’s ALL hair. Hair is a defining characteristic of mammals. Even whales and dolphins have hair (usually just a few on their snout as babies). “Fur” is just one type of hair.  Both human hair and animal fur is made of the same stuff that makes up rhinoceros horn and our toenails – a protein called keratin. Cats’ whiskers and porcupine quills are special kinds of hairs. Even the strange scales on the back of a pangolin are specially adapted hairs. Just like in humans, hairs with round shafts are straight, and curly hairs are flattened to various degrees.
When talking about pet hair and specific breeds of cats and dogs, “fur” is usually used to refer to a double coat of hair that covers the entire body. “Hair” is usually a finer, softer, longer, single coat and - as in the case of humans, the Sphynx, and the Devon and Cornish Rex breeds of cat - may not cover all of the body.

An often-repeated humorous quotation (author unknown) about hair versus fur is:

Dogs and cats: If it's where it belongs (on the animal), it's fur; if it's where it doesn't belong (on your black slacks), it's hair.

            Humans: If it's where it belongs (on the top of your head), it's hair; if it's where it  

            doesn't belong (on your back), it's fur.

Many people consider “hair” to be less allergenic than fur, but hair is not the culprit when it comes to allergies. The real culprits that stimulate allergic reactions are a number of proteins in a cat’s saliva and other glands in the body. They are deposited on the surface of the cat as he grooms and secreted from the sebaceous glands in the skin. These allergens mix with the surface of the skin and coat, and are then shed into the environment, naturally. It is true that some breeds that shed less and have finer hair are less likely to build up allergens within the coat and less likely to spread as much allergenic material in the environment, but even Sphynx cats groom themselves and have sebaceous glands, so are not truly allergy-free! For more information about why people are allergic to cats, stay tuned for our next blog article!

Meanwhile, if you are overwhelmed by your cat's shedding, you could put the cat hair to use!
Check out this book about crafting with cat hair or take a look at Flora Davis' cat hair jewelry.