Seasonal Allergies in Dogs

Summary

Seasonal allergies are a common condition in dogs. Most seasonal allergy symptoms in dogs result from exposure to flea saliva and/or pollen. Even though allergies cannot be cured, dogs with seasonal allergies have a good prognosis with appropriate management. 

The most common symptom of seasonal allergies is itchiness. In some cases, dogs also show respiratory symptoms such as sneezing and a runny nose, similar to humans with hayfever.  Diagnosis of seasonal allergies is complex. A combination of patient history, test response to therapy, and intradermal allergy testing is usually required to confirm diagnosis.

Most seasonal allergies respond well to a combination of allergen avoidance strategies along with itch-relief medications. More severe cases may require specialized immunotherapy to manage symptoms.

Risk Factors

Seasonal allergies are very common in dogs and typically manifest with a variety of itchy skin symptoms. In severe cases, excessive scratching causes hair loss, reddening of the skin, skin damage, and skin infections. These dogs are uncomfortable and require prompt veterinary attention, but are not expected to experience life-threatening symptoms.  

Removing the allergen from the environment results in complete resolution of symptoms, but this is only practical for dogs who are allergic to an easily-removed allergen like flea saliva.  The prognosis for seasonal allergies is usually good with aggressive, ongoing treatment. Since allergies cannot be cured, symptoms are expected to return whenever the dog is exposed to their specific allergens if they are not on medication. 

Possible Causes

As with allergies in humans, the cause is unknown. Some breeds have been shown to have predisposition to allergies, but there is no definitive cause of the immune system reaction to allergens. The determining factor that makes an allergy “seasonal” is that it occurs during a particular season of the year. While not always seasonal, the allergic skin disorders that have the potential to be seasonal include:

Flea allergy dermatitisAtopic dermatitisContact dermatitis

Main Symptoms

The most common symptom of seasonal allergies is severe itch (pruritus). The most common itchy areas are the armpits, groin, muzzle, and paws. Symptoms of itchiness in dogs include:

• Excessive scratching • Biting or licking the area • Rubbing against surfaces • Rolling on the ground

Excessive licking of the anal region • “Scooting” or dragging the rump on the ground

Less commonly, some dogs develop respiratory symptoms with seasonal allergies, similar to people with hayfever. These symptoms include:

• Red, swollen eyes • Runny nose with clear fluid • Sneezing

Detailed Characterization

Dogs that are severely itchy cause damage to their skin from their scratching. In some cases, this damage results in skin infections. Symptoms include:

• Reddening, swelling, or crusting of the skin • Hair loss • Darkening of the skin • Foul odor

• Raised, blister-like bumps on the skin  • Weeping, open sores • Thickened skin

• Pus or blood oozing from the skin • Foul-smelling greasy buildup on the skin

In some cases, seasonal allergies cause ear infections. Symptoms of ear infections include:

• Head shaking • Scratching at the affected ear • Dark discharge from the affected ear • Foul odor

• Reddening of the skin of the ear canal • Swollen skin inside the ear flap and canal with an orange-peel texture

Dogs presenting with any of these symptoms require prompt veterinary care.

Testing and Diagnosis

The dog’s history and physical exam are often adequate to suggest seasonal allergies.

Useful diagnostic tests for ruling out other itchy skin conditions include: 

• Skin scraping • Fungal culture • Flea combing • Hair analysis • Skin/ear cytology • Skin biopsy

To confirm the specific allergens the immune system reacts to, an intradermal or skin patch test is used. In these tests, suspected allergens are placed against or injected into the skin to see how the dog responds. If the dog develops redness or itch, a diagnosis of allergy is confirmed.

Steps to Recovery

Allergies are a life-long condition. Appropriate medical management and minimizing exposure to allergens are the best tools for providing relief to keep allergic dogs comfortable and prevent secondary skin and ear infections.  

These strategies include using flea preventatives, bathing the dog, and cleaning bedding and carpets. While they don’t cure the dog’s allergies, anti-itch medications (available as both oral medications and injectables) provide the itch relief necessary to keep allergic dogs comfortable and prevent secondary skin infections. 

Some dogs show significant improvement when they are forced to walk through a foot bath upon returning inside when pollen levels are high. Thoroughly cleaning the dog’s environment through vacuuming, washing bedding and toys, and air filtration systems are also helpful strategies for minimizing symptoms. 

Allergy management medications are indicated for most dogs experiencing symptoms of seasonal allergies. These medications include:

• Antihistamines • Steroids, either oral or topical • Anti-itch medications

When avoidance and symptomatic therapy don’t provide adequate relief of allergy symptoms, a more aggressive diagnostic and treatment plan is necessary. Intradermal skin testing is used to identify specific allergens for immunotherapy, where small amounts of allergens are injected into the skin repeatedly over several months. Over time, the immune system reacts less to the injected allergen(s).

Prevention

Since the cause of allergies is unknown, there is no way to prevent them. Once allergies have been diagnosed, symptoms can be minimized or even prevented by avoiding the allergen completely. Having a complete assessment and diagnosis will help determine strategies to reduce exposure and symptoms in an allergic dog.

Are Seasonal Allergies Common in Dogs?

Seasonal allergies are very common in dogs.

Typical Treatment

Typical treatment of any allergies, including seasonal, includes a combination of:

• Eliminating the allergen • Anti-itch medications • Allergen immunotherapy

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