Pet allergies cause your immune system to react to substances in animals that are normally harmless. Symptoms include itchy eyes, stuffy nose, hives and sneezing. Treatment involves medications. You can prevent pet allergies by avoiding animals, using air filters, cleaning and brushing and bathing your pets regularly.
Pet allergies are certain proteins — called allergens — on your pet that cause your allergic immune system to overreact. These allergens are in animal fur, skin, urine (pee) and saliva (spit). It’s also in pet dander, which is tiny scales from your pets’ skin, hair or feathers.
Usually, these proteins are harmless. However, your allergic immune system views them as harmful “invaders,” like bacteria or viruses.
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Any pet can produce allergens, though cats and dogs are the most common source of pet allergens.
Other pets that cause allergies include:
Some people believe that certain breeds of furry pets are hypoallergenic (won’t cause allergic reactions) because they shed less fur. However, studies show that there aren’t any hypoallergenic furry animals, especially since pet allergens are more than fur alone.
Your body is unique. If you have pet allergies, certain breeds of furry pets may cause minor symptoms or no symptoms. However, healthcare providers and researchers can’t accurately predict which breeds will be the least irritating.
Animals that don’t have fur or feathers are the least likely to cause pet allergies. These include:
Pet allergies can affect anyone.
You’re more likely to have or develop pet allergies if your biological parents have pet allergies.
Pet allergies are common. Up to 30% of people in the U.S. are allergic to cats and dogs. You’re more than twice as likely to be allergic to a cat than a dog.
Pet allergies cause an allergic reaction. An allergic reaction is your body’s response to an allergen.
If you have allergies, the first time you encounter a pet allergen, your body responds by creating immunoglobulin E (IgE). IgE is an antibody that your immune system makes. Each type of IgE is sensitive to a specific kind of pet allergen and other allergens.
You may only have IgE antibodies that are sensitive to one particular animal. Or you may have many IgE antibodies that are sensitive to many different types of allergens.
The antibodies find the allergens in your body and help remove them by taking them to the mast cell (the allergy cell), where they attach to a special receptor. This causes the allergy cell to release histamine. Histamine is what causes your allergy symptoms.
Pet allergy symptoms include:
Pet allergies share many of the same symptoms as other illnesses, including influenza (flu) and the common cold. If you’re not sure whether your symptoms result from pet allergies or an illness, reach out to your healthcare provider. They can help you determine the cause of your symptoms.
Yes, pet allergies can cause fatigue (tiredness). When IgE and histamine cause nasal passage inflammation, you may feel tired.
Some pet allergy symptoms, including nasal congestion and coughing, can make it difficult to fall asleep and stay asleep. Interrupted or restless sleep can contribute to your fatigue.
It depends on the severity of your pet allergies.
If you have severe pet allergies, symptoms may appear within 15-30 minutes of encountering a pet.
If you have mild pet allergies, symptoms may appear a few hours to a few days after encountering a pet.
No, pet allergies aren’t contagious. You can’t spread pet allergies to another person.
If you notice you have allergy symptoms after being around pets, it’s a good idea to see your healthcare provider. They may refer you to an allergist. An allergist is a healthcare provider who specializes in allergies. They can help diagnose your pet allergies through specific tests.
Before conducting pet allergy tests, they may ask you questions, including:
Your healthcare provider may use different allergy tests to help diagnose your pet allergies based on your symptoms. These tests may include:
This test exposes your body to small amounts of different pet allergens.
Your healthcare provider will first clean a test area of your skin with iodine or alcohol. The test area is usually on your forearm or upper back.
Your allergist will place droplets of possible pet allergens on your skin. They then use a thin needle (lancet) to scratch your skin lightly. The droplets will enter your skin through the scratch. You’ll only feel slight discomfort, and you likely won’t bleed.
Allergic reactions typically occur within 15 minutes of exposure to possible pet allergens. Reactions may include skin discoloration (red, gray or white) or raised, round spots called wheals (a hive) that look like bug bites.
Your allergist will measure the size of your wheal and record what allergen caused the reaction.
A skin prick test takes less than an hour.
During a blood test, your healthcare provider will use a thin needle (21 gauge, slightly smaller than the size of a standard earring) to withdraw a small amount of blood from a vein in your arm. The blood sample goes to a laboratory. The lab will spin your blood down and use the plasma (yellow portion), which has the IgE, and places it in a testing plate coated with allergens. They’ll then place another chemical, which measures the amount of IgE present for that allergen. If you have high levels of IgE antibodies in your blood sample, you may have pet allergies.
It may take a week or longer to have the results from the blood test sent to a lab.
You can’t get rid of pet allergies. However, you can take OTC antihistamine pills, nasal corticosteroids and nasal antihistamines to treat your symptoms.
For some people, allergy shots (immunotherapy) offer a long-term solution to managing pet allergies. Each time you get an allergy shot, your body responds by lowering your sensitivity to the allergen. In some people, allergy shots may help prevent pet allergy symptoms even after they have stopped receiving treatment.
Talk to your healthcare provider about what treatment options are best for you.
Antihistamine side effects may include:
One study reported increased depression in people who took the antihistamines cetirizine and hydroxyzine. However, studies haven’t explored the effects of all antihistamines on mood disorders.
Nasal corticosteroid side effects may include:
Usually, the only side effects of allergy shots are discoloration, irritation or swelling at your injection site.
In rare cases, allergy shots may cause serious reactions, including anaphylaxis. Severe reactions usually occur within 15-30 minutes after receiving an allergy shot. You should wait at your healthcare provider’s office for at least 30 minutes after receiving an allergy shot in case you need emergency medical attention.
Once you’re no longer around pet allergens, your symptoms usually go away after a few hours. However, if you have severe pet allergies, your symptoms may last for several days. If you have pet allergies, showering and washing your clothes can speed your recovery from allergy exposure.
Antihistamines start to work about 30 minutes after you take them. They’re most effective within the first few hours.
Nasal antihistamines may start working as fast as 15 to 30 minutes.
Nasal corticosteroids may take at least two weeks for you to start feeling better.
If you’re around animals a lot, your healthcare provider may recommend that you take antihistamines every day to prevent symptoms.
The best way to prevent pet allergies is to avoid animals that trigger allergic reactions. You can also take antihistamines daily to help control your pet allergy symptoms and reduce your allergic reaction.
If avoiding pets isn’t possible, the following tips can help prevent symptoms or reduce the severity of your symptoms.
In severe cases, you may need to find a new home for your pet.
Living with a pet allergy can be challenging. Most symptoms are mild, but some may cause breathing problems. Most people can control their pet allergies with medications.
You can’t cure pet allergies, but you can control your symptoms by avoiding pets that have known allergens and taking medications.
See your healthcare provider if you regularly have pet allergy symptoms, especially if they affect your day-to-day quality of life.
A note from Cleveland Clinic
Pet allergies can be frustrating, especially if you don’t know what animals trigger your immune system response. If you have symptoms of pet allergies, reach out to your healthcare provider. They can work with you to determine if your symptoms are from a common illness or pet allergies. They can also refer you to an allergist to help you figure out which animals cause the most significant allergic reaction.
Last reviewed by a Cleveland Clinic medical professional on 10/04/2022.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy