Cat and dog allergy

What is pet allergy?

Pet allergies occur when the immune system reacts to the saliva, dead skin cells (dander) or urine of pets.

About 1 in 5 people have a pet allergy. Most are allergic to cats or dogs, but you can also be allergic to other domestic animals, such as guinea pigs, mice, rats, horses and birds. Allergies are particularly common in people who handle pets as part of their job. Some people are allergic to more than one animal.

People with a pet allergy are also likely to have other allergies — for example, to pollen and dust mites. Pet allergies can develop at any time during childhood or adulthood, but some people will grow out of them.

How does pet allergy occur?

Pet allergens (the substances that cause the allergic reaction) are most concentrated in homes with pets. But they are also found in buildings and public spaces without pets.

The main source of dog allergen is saliva, either directly from licking or from being transferred to their dander or hair. Cat allergens mainly come from glands in their skin and are spread through licking and grooming.

Pet allergens are sticky and can remain for months or years after a pet has gone. They can become airborne and attach to clothes and hair.

People can become sensitive to, or have an allergic reaction to, cats or dogs without ever having owned a pet.

Symptoms of pet allergy

Pet allergy can cause:

• sneezing
• hay fever
• wheezing or asthma
• itching
• rash (hives)

Symptoms might appear as soon as you pat a cat or dog, or they might take a few hours to appear.

Pet allergies are rarely life-threatening. But if you think someone is having a severe reaction such as anaphylaxis, and their breathing is affected, call triple zero (000) and ask for an ambulance.

How is pet allergy diagnosed?

A diagnosis of pet allergy is made based on your medical history and a physical examination. Your doctor might refer you to an allergy specialist for a skin-prick test or blood test for confirmation.

Avoid online or over-the-counter allergy test kits or other unconventional allergy tests. Many are not evidence-based, and don’t provide accurate results.

In particular, avoid unproven tests and treatments such as applied kinesiology, the Vega test, hair analysis, serum-specific IgG tests, Nambudripad’s Allergy Elimination Techniques (NAET), and cytotoxic tests such as ALCAT, FACT and Bryan’s test.

See your doctor for advice.

Living with pet allergy

The best solution to pet allergies is to avoid exposure — for example, by not having a pet in your home. Often, the only solution is to find the pet a new home. You should also avoid smoking, as this makes allergies more likely to develop.

Washing the pet, restricting it to one area of the house, using high efficiency particulate air (HEPA) cleaners and removing carpet haven’t been shown to work.

If you have a pet allergy, always wash your hands after touching the animal and never let it into your bedroom.

If you can’t avoid exposure, you might be able to treat the symptoms with medication, such as:

• antihistamines
• nasal steroid sprays
• decongestants

Another option is immunotherapy, which is also known as ‘desensitisation’. It’s offered by a specialist known as an immunologist, and takes 3 to 5 years to complete.