Dog Allergies in Spring in Washington: Timing, Triggers, and What to Do About Them

If your dog starts scratching relentlessly, licking their paws raw, or shaking their head the moment Washington’s trees begin to bloom, you are not imagining things. Spring in Washington State is one of the most challenging times of year for allergy-prone dogs, and the season arrives earlier — and lasts longer — than many owners expect.

Understanding what triggers your dog’s spring allergies, how to recognize the symptoms, and what your vet can do to help will put you in a much better position to manage your dog’s comfort throughout the season. This guide covers everything you need to know, from the first pollen release in late winter through the height of allergy season in May.

When Does Spring Allergy Season Start for Dogs in Washington

Washington’s allergy season is decently long, beginning in very early spring and going until late fall. For your dog, that means the window of potential discomfort is wide — and the start date may surprise you.

Winters can be mild and wet in Washington, so seasonal allergies will commonly begin in February. Trees will often start producing pollen as early as February, which means your dog’s immune system may already be reacting before the calendar officially flips to spring.

In Washington, you’ll want to keep an eye on pollen counts in April, May, and September — these months are when seasonal allergies are typically at their peak. For dogs, that peak period often brings the most intense symptoms, so it pays to start monitoring your dog’s behavior and skin condition well before April arrives.

Pro Tip: Check the daily pollen forecast for your Washington city starting in late February. On high-pollen days, limit your dog’s outdoor time during mid-morning hours when airborne pollen concentrations tend to be highest.

The timing also varies depending on where in Washington you live. Western Washington, including cities like Seattle, Tacoma, and Olympia, is known for its damp climate and lush greenery, and this region sees high levels of tree pollen, particularly from cedar, alder, and pine trees, in the spring. Eastern Washington, encompassing Spokane, Yakima, and the Tri-Cities, has a drier climate, and tree pollen especially from pine and oak trees is common in the spring.

What Causes Dog Allergies in Spring in Washington

Spring allergies in dogs are triggered by environmental allergens — substances that the immune system mistakenly identifies as threats. When a dog with allergic tendencies is exposed to these substances, their immune system overreacts, causing the inflammation and irritation that owners recognize as allergy symptoms.

Spring in Washington is when tree allergies peak, and the primary culprits for tree allergies include cedar, alder, willow, oak, birch, and juniper trees. In the Seattle, Tacoma, and Everett areas specifically, spring allergies are usually due to walnut, willow, oak, and ash trees.

Pollen is not the only concern. As the spring season brings more rain and blooming trees, the damp, shaded areas created become ideal breeding grounds for mold, which can trigger allergic reactions. Washington’s notoriously wet spring climate makes mold spores a particularly relevant allergen for dogs in this state.

• Tree pollen – cedar, alder, willow, oak, birch, and juniper are the primary spring offenders in Washington
• Mold spores – thrive in Washington’s damp spring conditions, especially in shaded or wooded areas
• Grass pollen – begins building toward late spring; ryegrass and bluegrass become prevalent in western Washington as spring transitions to summer
• Dust mites – other environmental factors such as mold, dust mites, and even the dander of people or other animals can exacerbate your dog’s allergic reactions
• Fleas – fleas are more prevalent in the spring, and their bites can lead to flea allergy dermatitis (FAD), causing itching and discomfort for your dog

Wind can carry allergens far and wide, affecting dogs even if they don’t spend much time outdoors. On top of that, allergens can cling to their fur and paws, making their way inside and continuing to cause discomfort long after your dog has come indoors.

Key Insight: Washington’s cool, damp spring climate creates conditions where both pollen and mold spores thrive simultaneously, which can mean your dog is reacting to multiple allergen types at once — making symptoms harder to pin down without veterinary testing.

Signs Your Dog Has Spring Allergies in Washington

Veterinarians report that allergy-related visits often rise in March as pollen, mold spores, and grasses become more prevalent in the Pacific Northwest. Dogs can react to these environmental allergens much like people do, though symptoms often appear on the skin rather than in the respiratory system.

Knowing what to look for helps you act quickly. The most common signs of spring allergies in Washington dogs include:

• Excessive scratching, licking, or chewing – constant itching is the most common indicator of dog spring allergies, with signs including excessive licking, scratching, biting, and scooting
• Paw chewing and redness – dogs frequently lick or chew their paws until the skin becomes irritated or raw
• Red, inflamed ears – if your dog is scratching their ears or continuously shaking their head back and forth, they could have an ear infection; additional signs include inflammation and redness in the ears
• Watery eyes and runny nose – dogs with allergies often develop watery eyes or a runny nose
• Sneezing – it is normal for your dog to sneeze on occasion, but excessive sneezing is a common side effect of seasonal dog allergies
• Hot spots and skin irritation – check your dog’s skin for signs of inflammation or hot spots, especially around the belly, groin, and armpits
• Respiratory changes – wheezing, difficulty breathing, or other respiratory problems could indicate the presence of allergies

Chronic allergies can lead to more severe health issues like persistent ear infections, skin diseases, and even respiratory problems. If you notice your dog’s symptoms worsening each spring or becoming harder to manage, that pattern itself is an important clue worth discussing with your vet.

Important Note: Food allergies and environmental allergies often have the same symptoms. However, environmental allergies are usually more prominent during spring, so if your dog’s symptoms get worse around this time of year, it’s more likely they’re reacting to pollen or mold than to their food.

Which Dog Breeds Are Most Prone to Spring Allergies

There isn’t a single breed that is most prone to allergies, but research shows that certain breeds are diagnosed with allergic skin disease (canine atopic dermatitis) more often than others. A genetic component is suspected because certain breeds and families of dogs are predisposed to this condition.

Many breeds of dogs are affected, including Labrador Retrievers, Golden Retrievers, Soft-coated Wheaton Terriers, West Highland White Terriers, Jack Russell Terriers, Bulldogs, Boston Terriers, Boxers, Pit Bulls, Shar Peis, Shih Tzus, and Weimaraners, as well as mixed-breed dogs.

Breeds with longer coats or skin folds (like Bulldogs, Retrievers, and Spaniels) may be more prone to trapping pollen, worsening their reactions. That said, any dog, purebred or mixed, can develop allergies, so it’s worth staying attentive regardless of your dog’s breed.

Washington State’s dense forests, abundant rainfall, and rich plant diversity mean that even dogs without a strong genetic predisposition may develop sensitivities over time. If you have a wildlife-loving dog who spends a lot of time exploring Washington’s outdoors, regular exposure to high pollen environments can increase the likelihood of sensitization.

How Vets Diagnose Seasonal Allergies in Dogs in Washington

Accurately diagnosing spring allergies in dogs is an essential step toward helping your pet find relief. The process typically starts with a thorough examination and a detailed discussion about the symptoms you’ve noticed.

Veterinarians typically begin by ruling out other causes of itching, including fleas, mites, or infections. Once those are eliminated, the focus shifts to identifying whether environmental allergens are the root cause.

The diagnostic process generally involves several steps:

1. Physical examination and history review – your vet will assess your dog’s skin, ears, and coat while asking about when symptoms appear and how they change with the seasons
2. Ruling out other conditions – flea allergy dermatitis, food allergies, and skin infections must be excluded before a seasonal allergy diagnosis is confirmed
3. Allergy testing – testing can be performed by observing how your dog’s skin reacts to injections of small amounts of allergens, or by taking a blood sample and testing for IgE antibodies to a panel of allergens
4. Intradermal skin testing – intradermal allergy testing can be used to identify allergens to be included in immunotherapy

Diagnosis is based on clinical signs, history, and exclusion of other causes of pruritus. Identifying specific triggers can be challenging, as dogs may react to multiple allergens simultaneously, which is especially common in Washington given the state’s diverse plant life and year-round moisture.

Pro Tip: Keep a symptom journal before your vet appointment. Note when symptoms started, which body areas are affected, whether they worsen after outdoor time, and any pattern you’ve noticed year over year. This information significantly speeds up the diagnostic process.

For dogs with complex or severe allergy cases, your vet may refer you to a veterinary dermatologist. More challenging cases may benefit from consultation with a veterinary dermatologist, and your veterinarian can help provide a referral if necessary or you can locate one through the American College of Veterinary Dermatology.

How to Treat Spring Allergies in Dogs in Washington

Once allergies are identified, treatment plans are tailored to the individual pet and may include medications to reduce inflammation and itching, medicated shampoos, dietary supplements, or long-term allergy management therapies.

Treatment options range from immediate symptom relief to long-term immune management. Here is a breakdown of the most common approaches:

Topical Treatments

One option is to give your dog an oatmeal bath, which can soothe itchy skin and reduce inflammation. Hypoallergenic shampoos designed for sensitive skin can also provide relief. For more localized itching or rashes, medicated creams or sprays can be applied to reduce irritation and prevent infection.

Antihistamines and Steroids

Antihistamines are an option for managing your dog’s allergy symptoms — always consult your vet for the appropriate dosage and type for your dog’s specific needs. For more severe allergic reactions, steroid medications may be prescribed to reduce inflammation and itching.

Omega-3 Fatty Acids

Adding omega-3 fatty acids to your dog’s diet through fish oil or supplements can improve skin health and reduce inflammation caused by allergies. This is a low-risk addition that many Washington vets recommend as a baseline support measure.

Allergen-Specific Immunotherapy (ASIT)

For dogs with persistent or severe seasonal allergies, immunotherapy is often the most effective long-term solution. Allergen-specific immunotherapy is the only treatment that can change a patient’s immune response to allergens and induce remission of clinical signs, and it remains the treatment of choice of most dermatologists and allergists.

Dogs with canine atopic dermatitis are known to develop IgE antibodies against environmental allergens, and allergen-specific immunotherapy remains a widely prescribed therapy known to clinically benefit approximately 60% to 70% of dogs. ASIT can be administered via injections or orally, which are equally effective; therefore, clients should choose a method based on the ease of administration.

Key Insight: Early intervention is key to preventing complications and keeping your dog healthy and happy during the allergy season. Starting treatment before peak pollen season in April and May gives medications time to take effect when your dog needs them most.

Dogs in Washington with year-round or multi-season allergies may benefit most from immunotherapy, since the state’s long allergy season — running from February through late fall — makes symptom management alone a significant ongoing effort.

How to Reduce Your Dog’s Exposure to Spring Allergens in Washington

Managing your dog’s environment is just as important as medical treatment. Because Washington’s spring brings heavy pollen loads from multiple tree species along with persistent moisture that encourages mold growth, daily allergen-reduction habits make a real difference.

After-Walk Routines

Since pollen and dust cling to your dog’s fur and paws, wiping them down with a damp cloth or pet wipes after walks can help reduce allergy flare-ups. Pay particular attention to paws, belly, and face — the areas most likely to contact grass and ground-level allergens.

Bathing

Give your dog regular baths during the spring to keep their fur and skin clear of any irritants. Use a soothing, oat-based dog shampoo to help calm your dog’s skin if they are itching.

Timing Outdoor Activities

You should avoid taking your dog for a walk when pollen levels are high. Pollen levels are typically at their highest in the morning and on dry, warm days. In Washington, rainy days actually provide some relief — rain washes pollen out of the air, making those afternoons a better time for outdoor exercise.

Indoor Air Quality

• Air purifiers help improve air quality in your home by capturing and eliminating some common contaminants that may contribute to your pet’s allergies — place your air purifier in the room your dog spends most of their time.
• Vacuum frequently, wash your dog’s bedding weekly, and use air purifiers to reduce allergens in your home.
• Keep windows closed on high-pollen days, which in Washington typically means dry, breezy days in April and May

Flea Prevention

Washington’s mild, wet spring creates favorable conditions for fleas. Maintaining consistent flea prevention year-round is essential for allergy-prone dogs, since flea allergy dermatitis can compound seasonal allergies and make it much harder to identify and manage the root cause of your dog’s discomfort.

Common Mistake: Many owners stop allergen-reduction routines as soon as their dog’s symptoms improve, only to see a flare-up return within days. Washington’s pollen season is long enough that consistent daily habits — not just reactive treatment — make the biggest difference in your dog’s comfort level.

Washington’s outdoor environment also exposes dogs to a wide variety of wildlife and insects during spring. Being aware of what your dog is walking through — from Washington’s ant species to venomous animals in Washington State — adds another layer of protection during outdoor adventures.

When to See a Vet About Your Dog’s Spring Allergies in Washington

Some allergy symptoms can be managed at home with the right routine, but there are clear situations where veterinary care is the right call. Knowing when to make that appointment helps you avoid letting manageable symptoms escalate into more serious problems.

Pet owners should contact a veterinarian if allergy symptoms persist for more than a few days, worsen over time, or interfere with a pet’s normal activity. Early intervention can improve comfort and reduce the risk of chronic skin problems.

Reach out to your vet promptly if you notice any of the following:

• Scratching or licking that has broken the skin or caused open sores
• Recurring ear infections, especially if they appear each spring
• Significant hair loss or hot spots that aren’t improving
• Signs of a serious allergic reaction, such as difficulty breathing or severe swelling
• Symptoms that started early (February or March) and are already interfering with your dog’s sleep or daily behavior
• Excessive scratching, biting, or licking resulting in open wounds or infections

Self-diagnosing your dog’s allergies and relying solely on home remedies can delay effective treatment and relief. Your veterinarian can perform allergy testing, prescribe medications that offer more targeted relief than OTC options, and recommend dietary changes or supplements that support skin health.

In-person veterinary care is required not only for diagnosing and treating allergies but also for preventing secondary infections that can arise from constant scratching and skin breakdown. Your vet can also help you develop an allergy management plan tailored to your dog’s specific needs, helping them enjoy the spring season with minimal discomfort.

Dogs with allergies in Washington face a long season, but with the right veterinary partnership and consistent daily management, most dogs can move through spring with significantly less discomfort. If your dog has struggled in previous years, consider booking a pre-season appointment in late January or early February — before the first pollen counts rise — so you are ready with a treatment plan when the season begins.

If you’re curious how Washington’s allergy season compares to other states, you can explore guides for dogs in Alabama, Alaska, Arizona, Arkansas, Colorado, Connecticut, Delaware, and Georgia to get a broader picture of how regional climates shape allergy season for dogs across the country.