Overview
Pet allergy is an allergic reaction to proteins found in an animal's skin cells, saliva or urine. Symptoms of pet allergy include those common to hay fever, such as sneezing and runny nose. Some people also may experience symptoms of asthma, such as wheezing and difficulty breathing.
Pet allergy is usually brought on by exposure to the dead flakes of skin shed by animals, called dander. Any animal with fur can be a source of pet allergy. The most common pet allergies are associated with cats and dogs.
If you have a pet allergy, the best strategy is to avoid or limit exposure to the animal as much as possible. Medicines or other treatments may be necessary to relieve symptoms and manage asthma.
Symptoms
Pet allergy symptoms typically include:
- Sneezing.
- Runny nose.
- Itchy, red or watery eyes.
- Nasal congestion.
- Itchy nose, roof of mouth or throat.
- Postnasal drip.
- Cough.
- Facial pressure and pain.
- Trouble sleeping.
- Swollen, discolored skin under the eyes.
- In a child, frequent upward rubbing of the nose.
If your pet allergy contributes to asthma, you also may experience:
- Difficulty breathing.
- Chest tightness or pain.
- Whistling or wheezing sound when exhaling.
- Trouble sleeping caused by shortness of breath, coughing or wheezing.
Skin symptoms
Some people with pet allergy also may have skin symptoms, a pattern known as allergic dermatitis. This type of dermatitis is an immune system reaction that causes skin swelling and irritation. Direct contact with an allergy-causing pet may trigger allergic dermatitis, causing symptoms, such as:
- Raised, discolored patches of skin called hives.
- Eczema.
- Itchy skin.
When to see a doctor
If your symptoms are severe — with nasal passages feeling completely blocked, wheezing and difficulty sleeping — call a healthcare professional. Seek emergency care if wheezing or shortness of breath quickly gets worse. Also seek care if you are short of breath with minimal activity.
From Mayo Clinic to your inbox
Causes
Allergies occur when your immune system reacts to a foreign substance such as pollen, mold or pet dander.
Your immune system makes proteins known as antibodies. These antibodies protect you from unwanted invaders that could make you sick or cause an infection. When you have allergies, your immune system makes antibodies that identify your allergen as something harmful, even though it isn't.
When you come in contact with the allergen, your immune system responds and causes swelling in your nasal passages or lungs. Exposure to the allergen can cause the long-lasting airway swelling associated with asthma.
Cats and dogs
Allergens from cats and dogs are found in their dander, saliva, urine and sweat and on their fur. Dander is a particular problem because it is very small. It can remain airborne for long periods of time with the slightest bit of air circulation. It also collects easily in upholstered furniture and sticks to your clothes.
Pet saliva can stick to carpets, bedding, furniture and clothing. Dried saliva can become airborne.
So-called hypoallergenic cats and dogs may shed less fur than shedding types, but no breed is truly hypoallergenic.
Rodents and rabbits
Rodent pets include mice, gerbils, hamsters and guinea pigs. Allergens from rodents are usually present in hair, dander, saliva and urine. Dust from litter or sawdust in the bottom of cages may contribute to airborne allergens from rodents.
Rabbit allergens are present in dander, hair and saliva.
Other pets
Pet allergy is rarely caused by animals that don't have fur, such as fish and reptiles.
Risk factors
Pet allergies are common. However, you're more likely to develop a pet allergy if allergies or asthma runs in your family.
Exposure to pets at an early age may help you avoid pet allergies. Some studies have found that children who live with a dog in the first year of life may have better resistance to allergies during childhood than kids who don't have a dog at that age.
Complications
Sinus infections
Pet allergy can cause ongoing swelling in your nose that may block your sinuses. These blockages may make you more likely to develop bacterial infections of the sinuses, such as sinusitis.
Asthma
People with asthma and pet allergy sometimes have a hard time managing asthma symptoms. They may be at risk of asthma attacks that require urgent medical treatment or emergency care.
Prevention
If you don't have a pet but are considering adopting or buying one, make sure you don't have pet allergies before making the commitment.
