Seasonal Allergies in Cats

Key takeaways

Whereas humans get sneezy and sniffly at certain times of the year, some cats get red, itchy skin and secondary skin infections for the same reason: seasonal allergies.

  • Allergy symptoms result from the immune system overreacting to otherwise harmless substances (allergens)
  • Common seasonal allergens affecting cats include pollen, mites, fleas, grasses, molds, and environmental pollutants
  • Symptoms of seasonal allergies in cats include red and itchy skin accompanied by excessive grooming, which often leads to secondary skin infections
  • Seasonal allergies are diagnosed based on the limited duration and seasonality of the symptoms, combined with trials where potential allergens are eliminated
  • As with all allergies, there is no cure to seasonal allergies, but there are many management options, and many ways to help reduce exposure to allergens
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A closer look: Seasonal Allergies in Cats

Along with the classic itching, scratching, biting, and excessive licking and grooming, there are three groups of symptoms associated with seasonal allergies which present themselves differently in each affected cat.
Skin symptoms are the most common group of symptoms and include: excessive shedding, dandruff, redness, dryness, open sores, scabbing, and lesions.

Respiratory symptoms include coughing, sneezing, a runny nose, red watery eyes, and wheezing. Coughing, wheezing, and difficulty breathing are symptoms of allergic bronchitis, also known as feline asthma. Some cats develop allergic bronchitis in response to environmental pollutants. If the cat develops difficulty breathing, emergency care is necessary. Digestive symptoms are rare but include diarrhea, flatulence, and vomiting.

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Risk factors

When skin gets red and itchy and cats begin scratching, biting, and excessively grooming themselves, taking immediate at-home action reduces the likelihood of secondary infections.

Medical attention is required to resolve allergic symptoms when:

  • The skin develops a bad smell
  • Lethargy or reduced appetite develops
  • Scratching results in hair loss
  • An infected patch of skin does not improve in 48 hours
  • Symptoms are severe or persistent

Emergency care is necessary if coughing, wheezing, or difficulty breathing develop.

Possible causes

Like any allergy, seasonal allergies are caused by the immune system overreacting to an otherwise harmless substance or trigger. The root cause of allergies is unknown, but there is some evidence of genetic predisposition. In general, seasonal allergies in cats fall into one of the following categories:

Parasites: Some cats are highly allergic to flea bites; this is called flea allergy dermatitis (FAD). As flea populations fluctuate with the seasons, flea allergy dermatitis presents as a seasonal allergy. Cats that are severely allergic to fleas may have non-seasonal FAD. Some cats are allergic to other parasites, such as mites, which are not necessarily associated with a seasonal increase in activity.

Airborne Irritants: Some cats have allergies to airborne allergens; this is called atopic dermatitis. When the airborne allergen has seasons of intensity, such as pollen, atopic dermatitis occurs seasonally.

Contact Irritants: While considerably rarer, some cats are allergic to things they come into contact with, like grass, shampoo, or wool. When the allergen is grass, fertilizer, or another irritant that grows or is used during certain seasons, it is considered a seasonal allergy.

Main symptoms

Testing and diagnosis

There is no definitive test for seasonal allergies, so diagnosis is based on elimination of other root causes. There are many potential causes of an itchy cat, so testing to rule out other conditions is the first step. These tests include:

  • Skin scraping
  • Fungal culture
  • Skin/ear cytology
  • Skin biopsy

Once allergies are suspected, the approach is usually two pronged: treat the symptoms while continuing to investigate the cause.

Allergy tests are available and may provide clues to potential allergens. These tests are not diagnostic on their own, as the test shows any allergen the cat has been exposed to, regardless of whether it is causing an allergic response. To confirm a diagnosis, the allergen must be removed for a period to see if symptoms resolve. If symptoms resolve, and return when the allergen is reintroduced, then an allergy to that allergen is confirmed.

Patch tests are another option for testing allergens. In these tests, the allergen is placed against the skin using a bandage or injected into the skin, to see if redness or itchiness develops. If symptoms occur, then an allergy is confirmed.

Steps to Recovery

As fleas are the most probable case of seasonal allergies, treatment of a potential case of seasonal allergies usually starts with flea control for the affected cat and other animals in the household as well as flea treatment for the household environment itself. In some cases, immunotherapy (allergy shots) may be effective for long term management of allergies. By increasing the dose over several subsequent injections, the patient develops immune tolerance to the allergen(s).

Other treatment options include supplements, prescription or over-the-counter antihistamines, ointments, and medications which help manage the allergy, but do not directly treat the underlying cause.

Allergies last a lifetime. By reducing exposure to the allergen, desensitizing the immune system to the allergen (if appropriate), and treating symptoms as they arise, affected cats can have healthy and symptom-free lives.


Since the underlying cause of allergies is undetermined, it is not possible to prevent a cat from developing them. Identifying triggers and limiting exposure to irritants is critical to preventing serious symptoms of allergies once they have been identified. Ideas to help with reducing symptoms include:

  • Applying witch hazel, dampened green or black tea bags, or coconut oil to irritated skin
  • Bathing with a mild shampoo to limit the amount of dander and remove allergens from fur and skin.
  • Wiping the cat’s feet with a washcloth, especially when coming inside after being outdoors
  • Washing points of high contact throughout the house to reduce allergen build up
  • Keeping doors and windows closed to reduce allergens introduced into the household
  • Using dust-free litter

Are Seasonal Allergies in Cats common?

Seasonal allergies are very common in cats.

Typical Treatment

  • Anti allergy medications
  • Steroids
  • Ointments
  • Allergy serum shots (immunotherapy)
  • Antihistamines

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