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When Do Allergies in Pets Appear? What is a Pet's Allergy Season? | VetDERM Clinic

When Do Allergies in Pets Appear? What is a Pet’s Allergy Season?


Allergies in pets can be quite like those in humans. They are an overreaction of the immune system again commonly encountered things in the environment. These can include pollen from grass and trees, fungus in the surroundings, house dust mites and animal dander within our houses to name a few common “allergy triggers”. 

Symptoms exhibited can vary from one individual to the next. Skin itchiness, skin rashes, respiratory signs, water eyes are some possibilities. Some pets may show all these symptoms, as well as additional signs such as hives and ear infections. Dogs are especially more prone to skin infection and ear infection from allergies, as compared to humans and cats. 


In dogs and cats, allergies can be seasonal and restricted to one or two seasons of the year. Or, allergy symptoms may be year-round! 


Pets with year round allergies will exhibit year round allergy signs. The symptoms do not have to be equally mild or severe throughout the year though! Often, year round allergic pets will have seasons of “allergic flares” where their symptoms tend to worsen, compared to the rest of the year.  

Seasonal allergies can be just that—seasonal. This means they occur only during certain times of year. Do keep in mind that seasonal allergies may progress from seasonal to non-seasonal. Also, if a pet exhibits allergy related problems in one season, this does not rule out milder allergies in other seasons (also called, subclinical symptoms; or symptoms that do not necessarily need medical help). To figure out what may be causing allergy symptoms in a pet, looking at the exact time of year in which your pet’s allergies occur can be helpful. 

Tree pollen allergies are most relevant in the spring season. And these allergies can be quite intense, as tree pollen can be flying everywhere! Grass and weed pollen are “warm weather” allergens, as these plants pollinate in the warmer months including early fall. Environmental molds can be strictly seasonal, or may be a year round allergen, depending on where you live. 


Mild and moist weather such as in Vancouver and Surrey can mean environmental mold is a year round problem, though worse from fall through spring. It is a more seasonal problem in Victoria and strictly seasonal in Saskatoon and Winnipeg, coinciding with snow mould!


House dust mites and human dander (as well as dander from other pets) are year round allergens. These form a normal component of our and our pet’s environment, no matter how clean the house may be! In certain home environments, these allergens may be most impactful during fall and winter months.

If your dog or cat has more than one of the above allergies, their allergies naturally become more complicated. It will become tough to follow and predict the season in which their allergy triggers and allergy flares happen. Your pet may transition from one allergy to another, without change in their symptoms. To further complicate allergies, inflammation from itchiness and skin infection can also limit your ability to follow seasonal changes.

Allergies Can Also Progress: Slowly or Rapidly

Seasonal allergy signs noted in some pets may not remain seasonal for long. As pets age, new allergies can develop over time. In some pets, this progression is quite rapid. In others, the progression may be slow and take years! As the severity of allergy progresses in a pet, they may become less responsive to treatments that worked in the past, or may start having more severe allergy symptoms. Thus, finding and controlling the underlying cause of allergies at a younger age is most desirable. 


After all, allergy is an incurable condition. The earlier we can control the signs and stop its progression, the better long term outcomes our pets will have. 


Signs of Seasonal and Non-Seasonal Allergies

When it comes to your pets having allergies, the symptoms normally present themselves as skin irritation or inflammation (allergic dermatitis) rather than as respiratory problems. In some cases, symptoms of respiratory problems can and will occur in addition to the dermatitis, such as a runny nose, watery eyes, coughing, and sneezing. 


In most allergic individuals, the dog or cat’s skin will become very itchy, they will scratch excessively, and they may bite or chew at certain areas of their body (often around the tail and/or their paws). They may also rub up against surfaces like furniture or carpet to relieve themselves of the annoying itch. Cats often over-groom themselves, even causing significant hair loss.


As your pet continues to scratch at their itchy parts, their skin will become inflamed and tender to the touch. They may get areas of hair loss, open sores on their skin, and scabbing. 

Pets with allergies also usually have issues with their ears. The ear canals will become itchy and inflamed. This reaction either takes part as a generalized allergic response or it will become infected with yeast or bacteria. When infected, the ears will often have a foul odour and discharge. 

Another major sign of seasonal allergies in pets to look for is redness of skin. Redness of skin is often due to inflammation, either from allergen contact or from trauma from itchiness, or both. Infection of the skin also adds to redness of skin.

What is a Pet’s Allergy Season?

As you may have guessed by now, the “allergy season” for each individual pet varies by the exact things it is allergic to! One pet may have summer allergies, while another may have winter allergies! Any pet’s allergies can turn into year-round allergies. Some pets may have year-round allergies right from the get-go! 

Often, environmental allergy symptoms are noted at a young age in a cat or a dog. Early diagnosis and control of the problem is key in limiting the impact of allergies in your pet. If you live with an older pet that has allergies, they can be helped too! Older pets can also benefit greatly from diagnosis of the allergy triggers and their specific treatment. 

Allergen avoidance, intra-dermal allergy testing (like the scratch test for allergen diagnosis in humans), allergy desensitization, rush immunotherapy (rapid desensitization), and nourishment of the skin barrier against allergens are just some tools that can help defend your pet against allergy triggers. We look forward to helping you and your allergic pet, if the need arises!

Creative Commons Attribution: Permission is granted to repost this article in its entirety with credit to VetDERM Clinic and a clickable link back to this page.



Dr. Jangi Bajwa is a Board certified veterinary dermatologist at VetDERM Clinic in Surrey BC. He is also the dermatology feature editor for Canadian Veterinary Journal. Dr. Bajwa’s special interests include otitis and allergic disease in pets; as well as helping improve quality of life of pets and their families.


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