It is estimated that upward of 10% of the population have at least some degree of sensitivity to cats. The severity of this allergy may range from the barely noticeable to quite severe.
Evidence suggests that cat allergies tend to appear in early adulthood and studies indicate that those who have been exposed to cats during their childhood are less likely to develop an allergy in later years1.
What causes allergies to cats?
Whilst most people assume it is the cat’s fur that is the cause of their allergic symptoms they are wrong. The actual main sources of the allergen are proteins found in the the cat’s sweat, saliva, urine and to a lesser extent, dead skin. Known as Fel d 1 and Fel d 4 these allergy-causing molecules are tiny; measuring less than 2.5 microns this makes them around the size of individual bacteria and one of the smallest allergens.
The miniscule size of these particles mean they readily become airborne and get everywhere. They may also be too small to vacuum away in all but the best HEPA filter equipped cleaners.
These particles are released in the greatest quantities when the cat washes itself.
Symptoms of cat allergy
Depending on how sensitive you are cat allergy symptoms can range from barely noticeable to actually affecting the quality of your life. The range of individual symptoms will be very familiar to sufferers of other allergies with itchy eyes, runny noses and rashes being the most common.
The speed at which these symptoms develop largely depends on sensitivity to cat allergens. For some it may appear almost the minute they encounter a cat, whilst for others who are less sensitive they may take hours or even days to appear – this is often the case if cat hair or dander gets onto your clothes.
The degree of contact required to trigger a reaction is also relative to how sensitive you are; for many it only requires entering a house where there is a cat to cause a reaction. In extreme cases it can occur long after the cat has gone.
The most common symptoms of cat allergy are:
- Sneezing and runny, itchy, stuffy nose
- Coughing, wheezing, possibly chest tightness and shortness of breath
- May bring on asthma
- Skin rash or hives – usually on the chest, face and/or neck
- Watery, red, itchy eyes
- Raised, red skin where a cat has scratched or licked you
Can cats cause asthma?
There is evidence that a relationship between cat allergy and asthma exists. One study found that 30% of asthma sufferers in the U.S were also allergic to cats [2. Arbes SJ, Gergen,PJ Vaughn B, Zeldin DC. Asthma cases attributable to atopy: Results from the Third National Health and Nutrition Examination Survey. Journal of Allergy and Clinical Immunology. September, 2007]. Another study found that exposure to cats caused asthma-like symptoms in a range of people who were not actually even allergic to cats [3. American Thoracic Society. “Exposure To Cats Increases Asthmatic Symptoms In People Without Specific Cat Allergy.” ScienceDaily. ScienceDaily, 2 July 2007].
What neither of these studies prove is that exposure to cats can actually cause asthma. However, there is plenty of evidence to show that breathing in microscopic cat allergens can trigger a severe asthma attack in nearly a third of people with asthma. Long term exposure to cats may also cause chronic asthma 2.
There are two ways of dealing with a cat allergy, neither of which are easy. The most obvious and effective method is to remove the cat from the home, but to many this is not an option. It is estimated that around a third of allergic cat owners don’t get rid of their pet, and instead.
If you do decide to find a new home for your cat this is just the start of your work. Cat allergens are long-lasting and you will therefore need to give your home a thorough cleaning several times to get on top of the source of your allergy. Once the cat has gone you might think about taking some of the following steps:
- Airing the house thoroughly to remove as much airborne allergen as possible
- Use a high-powered HEPA vacuum cleaner to remove allergen from as many surfaces as possible
- Wash as many furnishing covers as possible. Eg. curtains, cushions, sofa covers etc. These can be cold washed as heat does not affect cat allergen
- Possibly replace bedding if your cat slept in on the bed. Certainly wash thoroughly.
- Sprays such as tannic acid or polysaccharides may be used on furniture to deactivate some of the allergen
If you do decide to keep your pet it will require a big commitment if you wish to minimise your symptoms. The best approach is to take a three-pronged attack; reduce allergens in your environment, reduce allergens from the cat and modify your interactions with the cat to reduce your exposure to allergens.
- The most effective way to lower exposure to cat allergens is by airing your house as well as possible. This means opening windows as often as possible.
- To prevent a build up of allergens you should consider replacing fabric soft furnishings and carpets with surface that can be easily wiped down such as wooden floors and leather furnishings.
- Regular cleaning is essential. Dust regularly and using a high-powered HEPA vacuum cleaner will make sure the particles of allergen are not just recirculated by trapping them in the filter. You might also want to try an air filter as these are quite effective against airborne cat allergens.
- One effective way to keep the cat’s allergen levels down is a weekly bath (if possible!). This has to be a bath as showering has been shown to be ineffective – only a thorough soaking works.
- Whilst the oral tranquilizer acepromazine is recommended by some there is little effective evidence to suggest this, or any number of other anti-cat allergy sprays are effective.
- Keeping your cat out of the house as much as possible will also help. You can make a comfy cat shelter in the garage or anywhere outside where it can sleep.
- If your cat does remain indoors, make sure you keep it out of the bedroom and off the bed. We spend more time in the bedroom than any other room so this can help reduce overall allergen exposure.
- Whilst difficult, you should try and minimise your direct contact with your cat. Avoid having your cat on your lap and if you do stroke your cat make sure to wash your hands afterwards.
There are a number of over-the-counter medications you can take depending on the symptoms you suffer. For itchy and runny noses oral antihistamines and steroid nasal sprays can be effective whilst itchy eyes may be treated with antihistamine eye drops. Treatment of asthma symptoms will depend on the severity of the reaction. As this may be very serious it might be essential to remove the cat from the home, if less so standard asthma inhalers can relieve respiratory symptoms.
A longer term solution may be so-called allergy shots or immunotherapy. This technique works by exposing the allergy sufferer to a series of small doses of the allergen either by injection or orally. The amount is gradually increased and this allows the allergic person to build up a tolerance to the allergen over time.
Whilst the treatment may take from months to years to be effective there is evidence that the effects are lasting.
The question many allergic cat-lovers ask is are there allergy-free cats? The simple answer is there aren’t any allergy-free or hypoallergenic cats. However, there are certain breeds of cat that may produce lower levels of allergens.
Amongst these are some you might expect; the fur-less Cornish Rex and Devon Rex cats, along with the short-haired Abyssinian cat are all said to produce lower levels of the Fel d 1 allergen. But, it is worth pointing out that it is actually nothing to do with the length of the hair that makes these breeds more allergy-friendly.
Other cat breeds which are said to produce lower levels of allergens include long hairs like the Siberian cat and Balinese cat.
Before rushing out and bringing one of these cats home it must be stressed that opinion is split on whether many of these cats do cause less allergy symptoms so you will need to find out for yourself.
Over recent years several companies have marketed hypoallergenic cats. The best known of these was Allerca who claimed to have successfully produced an allergy-free cat. Unfortunately no evidence or independent support backed up these claims and the company has ceased breeding the cats.
Other companies have also claimed to have produced a hypoallergenic cat with Felix Pets 3 among them.
Whilst there may or may not be allergy-free cats there is a proven difference in allergen levels produced by male and female cats with tom cats producing more allergens. It has been shown that the levels of allergen production declines after male cats are neutered [6. Sex difference in Fel d 1 allergen production]. Slightly less certain is the relationship between cat color and allergen levels; one study has suggested that darker cats are more allergenic than light-colored cats.
Can you be allergic to cats but not dogs?
Twice as many people are allergic to cats as are allergic to dogs 4. This alone should make it clear that it is possible to be allergic to cats but not dogs. The reason for this is that the proteins that cause cat allergies are specific to cats, as are those that cause dog allergies.
This means that if you want a pet but are allergic to cats then you will be better off with a dog. We do realise though that people are often either “dog people” or “cat people” so this may not be the answer.