How Long Do Pet Allergy Symptoms Last?: Overcoming Pet Allergies


Pets can be wonderful companions that bring joy and comfort to our lives. However, for people with pet allergies, being around furry friends can cause miserable symptoms. Pet allergies are estimated to affect around 10-15% of the population.

The most common pets that trigger allergies are cats and dogs, but people can also be allergic to rodents, birds, and other furry animals. The culprit behind pet allergies is not the fur or hair itself, but proteins found in the pet’s dander (skin flakes), saliva, and urine.

When someone with a pet allergy is exposed to these allergens, their immune system overreacts and releases histamine, causing allergy symptoms.

In this article, we will discuss the common symptoms of pet allergies, how long they typically last, and ways to find relief.  

What Are The Common Pet Allergy Symptoms?

The most common pet allergy symptoms affect the nose, eyes, skin, sinuses and airways.

What Are The Common Pet Allergy Symptoms

Typical symptoms include:

  • Sneezing
  • Runny or Stuffy Nose
  • Red, Itchy, Watery Eyes
  • Coughing or Wheezing
  • Postnasal Drip Down The Throat
  • Itchy Mouth, Throat Or Ears
  • Facial Pressure and Headaches
  • Rashes, Hives, Eczema Flares

In more severe cases, a pet allergy can trigger asthma attacks. The asthma symptoms may consist of chest tightness, shortness of breath, coughing, and wheezing. Pet allergies can also worsen atopic dermatitis, a chronic skin condition that involves intense itching, redness, and dryness.

The type and severity of pet allergy symptoms can vary not only from person to person, but also seasonally. Many people find their pet allergies worsen during the spring and fall seasons when pollen and mold allergies are also higher.

How Long Do Pet Allergy Symptoms Last?

Pet allergy symptoms typically begin 10 to 20 minutes after exposure to the pet and can last for hours or even several days. Allergy relief medications like antihistamines work by blocking the release of histamine, the chemical responsible for symptoms.

Most over-the-counter antihistamines take about 30 minutes to 1 hour to provide relief, and the effects last for 4 to 6 hours. Nasal steroid sprays take longer to work, but relief lasts up to 12 hours. 

Once the allergens are removed, either by leaving the environment with the pet or thorough cleaning, it takes 4 to 6 hours for allergen levels to significantly decrease. However, pet allergens are very sticky and can remain present in an area for weeks or months.

For example, pet allergens cling easily to fabrics, carpets, walls, furniture, and even clothing. Vacuuming or washing fabrics will help remove the allergens faster so symptoms resolve more quickly. If allergy treatment is discontinued while you are still in contact with the pet allergens, symptoms will likely return within 4 to 6 hours.

How To Treat Pet Allergies

While the only surefire way to prevent pet allergy symptoms is avoiding exposure, there are medications and environmental measures that can help provide relief:

  • Antihistamines – Oral antihistamines like loratadine (Claritin), cetirizine (Zyrtec), or fexofenadine (Allegra) can block histamine and control symptoms of sneezing, sniffling, and itchy eyes. They are available over-the-counter or by prescription.
  • Nasal Steroids – Nasal steroid sprays like fluticasone (Flonase) and triamcinolone (Nasacort) can reduce inflammation in the nasal passages and sinus cavities. Prescription strength is often more effective for pet allergies.
  • Immunotherapy – Allergy shots or oral/sublingual immunotherapy involves gradually exposing the patient to the pet allergens in increasing doses. Over time this can desensitize the immune system to the allergens. 
  • Air Purifiers With HEPA Filters – HEPA filters help remove pet dander and other allergens circulating through the home.
  • Limit Fabrics – Remove carpets, drapes, and upholstered furniture which easily collect pet allergens. Stick to hard flooring and washable fabrics.
  • Create Pet-Free Zones – Designate areas like bedrooms off-limits to pets so you have an allergen-free sanctuary. Use high-efficiency air filters in these rooms.
  • Bathe Pets Frequently – Bathing your pet at least once a week will reduce the level of allergens in the home.
  • Vacuum and Clean Often – Use a vacuum with a HEPA filter and wash linens and blankets frequently in hot water to remove allergens.

For people with severe pet allergies, medications like steroids or biologics that control the immune response may be needed to manage symptoms. Allergy testing can help pinpoint specific pet allergies. Consulting an allergist can help devise an effective treatment plan.


Pet allergies are frustrating, but managing environmental exposures, taking medications as needed, and seeing an allergist for appropriate treatment can help.

While symptoms may hang around for hours or days after exposure, a proactive treatment approach can minimize the allergy misery and allow pet owners to enjoy time with their furry companions.

With the right strategy, people with pet allergies can often still tolerate being around pets and avoid having to remove them from the home.


Q1: How Long After Being Exposed To a Pet Will Allergy Symptoms Start?

Pet allergy symptoms typically begin within 10-20 minutes after exposure. However, it can sometimes take 1-2 hours for symptoms to fully develop.

Q2: Can Pet Allergy Symptoms Develop Or Worsen Over Multiple Exposures? 

Yes, symptoms may worsen or become more apparent over repeated or prolonged exposure to pet allergens. This is because the immune system can become more sensitized over time.

Q3: How Long After Removing Pet Allergens Will Symptoms Go Away?

It takes 4-6 hours for pet allergen levels to significantly decrease once the pet and its allergens are removed. However, symptoms usually start improving within 1-2 hours. Medications like antihistamines provide more rapid relief.

Q4: Can Pet Allergies Cause Symptoms All Over The Body?

Yes, pet allergies can cause systemic symptoms in addition to nasal and eye symptoms. These may include itchy skin, hives, coughing, wheezing, nausea, or diarrhea. Severe systemic reactions are less common.

Q5: Do Hypoallergenic Pets Produce Fewer Allergens? 

There is no truly “non-allergenic” pet. But some hypoallergenic breeds may produce less of the major cat and dog allergens. Consult an allergist to see if a hypoallergenic pet may be tolerated better.

Dr. Jun Ren is a dedicated and experienced registered dietitian and nutritionist who is committed to helping people achieve their health goals through personalized nutrition plans. With a passion for promoting healthy eating habits and preventing chronic diseases, Dr. Ren has been able to assist numerous clients in improving their overall quality of life.

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