Pet Allergy - Causes, Symptoms, Diagnosis, Prevention & Treatment

Pet Allergy

Authored by DesiMD Doctor on 14 Sep 2015 - 16:03.


Pet allergy is an allergic reaction caused by the proteins present in the skin, saliva and urine of the pet animals. The signs of pet allergy are similar to those of hay fever which include runny nose and sneezing and some people may also experience symptoms of asthma such as difficulty in breathing and wheezing.

The most common cause of pet allergy is the protein present in the dead skin cells or dander of the pet animal. Fur of any animal can be the cause of allergy, but the most common pets known to cause allergy include cats, dogs, horses and rodents.

The best method to prevent pet allergy is to avoid exposure to the animals, although medicines can be given to reduce the symptoms of allergy.

The body's immune system produces antibodies against the foreign bodies entering the body. This is followed by an inflammatory response which causes allergic reaction in the body. The foreign bodies which can trigger such reaction include pollen, mold or pet dander.

Cats and dogs: Cats and dogs can cause allergy by their dander (dead skin cells), saliva, sweat or urine. The most common cause of all these is dander as it is airborne due to its light weight. It can get into air by the slightest movement of air and can also deposit on upholstery and clothes. The saliva of cats and dogs can stick to bedding, furniture, clothing and carpets and can become airborne upon drying.

Rabbits and rodents: The allergens of rabbits are present in hair, dander and saliva. Rodents which are kept as pets include mice, hamsters, guinea pigs and gerbils. Rodent allergens are found in their hair, saliva, dander and urine. These allergens may get airborne form the dust of the litter of the animals present at the bottom of their cages.

Other pets: Some other pets that rarely cause allergy include fishes and reptiles.



Pet allergies cause nasal and dermal symptoms.

Nasal symptoms:

  • Runny nose
  • Sneezing
  • Nasal congestion
  • Red, itchy or watery eyes
  • Itchy nose, throat or palate
  • Cough
  • Facial pain and pressure
  • Swollen skin under eyes

If the allergy is severe or for prolonged durations the following symptoms of asthma may also be experienced:

  • Difficulty in breathing
  • Pain or tightness in chest
  • Wheezing
  • Difficulty in sleeping due to shortness of breath, wheezing or coughing

Dermal symptoms:

In some people the symptoms of skin are also seen. These include:

  • Hives (raised, red patches on skin)
  • Eczema
  • Itchy skin


Pet allergy may be suspected by the physician, based on the symptoms and the answers given by the patient. The physician also looks for the inflammation of the nasal lining. In pet allergy, the lining becomes bluish or pale.

The following tests are used in the diagnosis of pet allergy:

Skin allergy test:

The physician may recommend a skin test for confirming the cause of allergy. The patient may be referred to an allergist for performing this test.

In this test small quantities of purified allergen extracted from the animal proteins are injected into the skin. This test is usually performed on the forearm on sometimes on the upper back.

After injecting the allergen, the physician or allergist observes the skin for allergic reactions after 15 minutes. If the person is allergic, then a red, itchy patch is developed on the skin at the site of injection. This test is safe and the symptoms go away within half an hour.

Blood test:

Blood test can be done when the skin allergy test can’t be performed due to presence of skin conditions or interactions with some drugs. In blood test, the physician may evaluate the blood for the presence of antibodies against the specific allergen. This test also helps to determine the extent a person is allergic to an allergen.



Avoiding the exposure to the allergens is the first step to be followed in treatment. Patients should avoid contact and surroundings of the pet animal they are allergic to. It is not completely possible to avoid the exposure as the patient may also get exposed to the allergens which are carried on the clothes of other people.

To control the symptoms of allergy, anti-allergic medications need to be given.

Anti-allergic medications:

The physician may prescribe any of the following drugs to reduce the symptoms of allergy:

  • Antihistamines: these drugs help in reducing the production of histamine by the immune system which is responsible for causing the allergic reaction. These drugs help to relieve the symptoms such as sneezing, itching and runny nose. Azelastine and olopatadine are antihistamine drugs prescribed for intra-nasal use. Fexofenadine, loratadine and cetirizine are antihistamine tablets available over-the-counter. Other antihistamine tablets available on prescription are levocetirizine and desloratadine.
  • Corticosteroids: These drugs can be given as nasal sprays or orally. The side effects are less in intra-nasal route as lower dose is given intra-nasally. Corticosteroids help to reduce the inflammation and other symptoms of allergy. Examples of corticosteroids include fluticasone, mometasone furoate, triamcilone and ciclesonide.
  • Decongestants: These drugs are given to help shrink the swollen tissues in the nasal passage to ease breathing of the patient. They are also given in combination with antihistamine drugs. Patients having hypertension, cardiovascular disease or glaucoma should not take oral decongestants as they increase the blood pressure. They should also not be given to men with enlarged prostate as it makes the condition worse.
  • Cromolyn sodium: It acts by preventing the release of immune system chemical responsible for causing allergy symptoms, thus reducing the symptoms. It is used as over-the-counter nasal spray. It does not have any serious side effects and is most effective when used before the development of symptoms.




Simple prevention steps include:

  • Avoid contact with the pet animals.
  • Keep the pets clean.
  • Use a HEPA vacuum filter at home.
  • Do not allow the pet animals inside bedrooms or places where more time is spent.
  • Maintain proper ventilation at home so that the allergens escape out.
*Disclaimer This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.