Seasonal allergies in dogs: what’s normal, what’s not, and how to help (Spring 2026)

If your dog is suddenly itchier than usual as spring arrives, you’re not imagining it, and you’re not alone. This time of year, vets like us get a wave of questions about seasonal allergies in dogs: paw licking, red skin, recurring ear infections, watery eyes, and that relentless “I can’t settle” itch.

The helpful thing to know is this: most allergy flare-ups are manageable, but they’re rarely “just a bit of itching”. If we don’t get on top of them early, we often end up treating skin infections, ear infections, hot spots, hair loss, and a very fed-up dog.

Let’s break down what causes Spring allergies, what symptoms to look for, and how to relieve allergies in dogs safely and sensibly.

What are seasonal allergies in dogs?

Seasonal allergies are usually a type of allergic skin disease called atopic dermatitis (atopy). It happens when a dog’s immune system overreacts to relatively harmless environmental allergens (like pollen or mould), triggering inflammation and itching. 

Unlike humans, dogs often show allergies through their skin and ears rather than sneezing. That’s why “hayfever” in dogs can look like scratching and chewing rather than a runny nose. 

Common spring triggers

Seasonal allergies can be triggered by a few main culprits:

• Tree, grass and weed pollens (often worse in Spring/Summer, depending on where you live) 
• Mould spores (can spike after damp weather) 
• Dust mites (these can be year-round, but flare-ups often happen when the skin barrier is already inflamed) 
• Flea bites (even one bite can trigger a big reaction in sensitive dogs, more on this below)

As well as pollen and mould, insect bites generally (including flea bites) can trigger a flare, and if your dog has flea allergies, even one or two bites can keep them itchy.

And yes, dogs can be allergic to grass. Many react after walks with face rubbing, belly irritation, and paw licking.

Dog seasonal allergy symptoms to watch for

The most common dog allergy symptoms we see include:

• Itchy skin (scratching, chewing, rubbing on furniture)
• Paw licking (often red, sore, or saliva-stained feet, where their toes look darker or browner than their other fur)
• Skin irritation on the belly, armpits, groin, face, or between toes
• Ear infections (head shaking, ear scratching, smell, wax build-up)
• Hair loss or thinning coat from chronic licking/scratching
• Hot spots (sudden, angry, moist patches)
• Watery eyes or mild eye redness (seasonal allergies in dogs’ eyes can happen, but it’s usually not the main sign)

If your dog is itchy and you notice an odour or see greasiness, scabs, or weeping skin, that often means a secondary bacterial infection or yeast overgrowth has set in, and that needs vet support. 

How long do seasonal allergies last in dogs?

This is one of the most commonly asked questions, and the honest answer is: it depends on the trigger.

• If it’s pollen-driven, symptoms may last weeks to months, often peaking during that particular pollen season.
• If it’s flea allergy dermatitis, the itch can linger up to two weeks after the last flea bite, even once fleas are gone.

Many dogs have predictable “flare seasons” every year. Keeping a simple note on your phone (first-itchy day, worse after certain walks, ear-flare dates) can really help your vet tailor a long-term plan.

Can dogs develop seasonal allergies later in life?

Yes. While many dogs show atopy at a younger age, pollen allergies can develop at any age. 

What matters most is not the age, but whether the pattern and symptoms fit, and whether we’ve ruled out the other common causes of itching.

The big three: seasonal allergies, fleas, and food

A common frustration for owners is that dog allergies can look the same. Here’s a practical way to think about it:

1) Flea allergy dermatitis (FAD)

This is one of the most common causes of intense itching. A dog can have very few fleas visible and still react dramatically. The classic areas are the lower back, tail base, and inner thighs, but it can spread to other areas. Itching may persist for up to two weeks after bites stop. 

Key action: keep your flea prevention fully up to date for every pet in the household.

Check out our ultimate guide to fleas on dogs and cats here.

2) Food allergies (including chicken)

Chicken allergies in dogs are talked about a lot, but specific allergenic ingredients vary from dog to dog. Some dogs are allergic to one ingredient, but many are allergic to more than one thing. Food allergy signs can include itchy skin, ear infections, and sometimes (but not always) gut signs.  Your vet will often talk to you about trying a course of special food designed not to trigger any food allergies.  If you do an elimination diet, it is important to make sure your pet is not exposed to anything other than the diet; no licking the plates in the dishwasher, snuffling things out on walks, or secret snacks from people feeling sorry for your dog!  It is also worth bearing in mind that some “hypoallergenic diets” may remove only one potential allergen, not all of them.  So, a hypoallergenic diet that eliminates wheat may not solve the problem for a dog that is allergic to chicken and dairy.

3) Environmental allergies (seasonal or year-round)

These often show as paw licking, face rubbing, recurrent ear issues, and seasonal patterns.

Many dogs have more than one of the above at the same time, which is why a step-by-step approach works best.

Can seasonal allergies cause diarrhoea in dogs?

They can, but it’s not the classic pattern. If diarrhoea is a major feature, we think more about:

• food-responsive disease/food allergy
• parasites
• stress
• other medical causes

If diarrhoea is persistent, frequent, or your dog seems unwell, it’s worth a vet check rather than assuming it’s seasonal allergies.

How vets diagnose skin allergies in dogs

There isn’t one perfect test that instantly tells us “this is a seasonal allergy”. Diagnosis is usually a combination of:

1. History and examination (where the itch is, seasonality, response to treatments)
2. Ruling out look-alikes (fleas, mites, ringworm, contact irritation)
3. Checking for infection (skin/ear swabs to look for bacteria/yeast)
4. Sometimes a diet trial, if food allergy hasn’t been ruled out. 

What about allergy testing and blood tests?

Allergy testing (blood testing/serology or intradermal skin testing) is mainly used to design immunotherapy (desensitisation “allergy shots” or drops). It’s not usually the first step for an itchy dog, for example.  This is because, whilst it can sometimes provide clues, it is not a reliable test for diagnosing allergies.

If your vet suspects a deeper issue (or symptoms don’t fit the usual pattern), they may recommend blood tests to rule out other conditions or to safely start certain long-term medications.

How to relieve allergies in dogs: what you can do at home

These are low-risk steps that often make a real difference:

• Rinse or wipe paws and belly after walks (especially after rolling in grass)
• Regular grooming to remove pollen from the coat
• Wash bedding weekly during your pet’s flare-up season
• Use a medicated shampoo if your vet recommends it (some shampoos help reduce bacteria/yeast and calm inflammation)

A quick note on “home remedies”: anything applied to skin can sting inflamed areas, and some products are toxic if licked. If you’re unsure, please check with your vet first.

Treatment options (and why we often combine them)

Most dogs do best with a “multimodal” plan, because we’re trying to:

1. reduce itch and inflammation (the immune response),
2. repair the skin barrier, and
3. prevent/treat infections.

Depending on severity, your vet may recommend:

• Managing the pet’s environment/diet
• Flea control (even if you “never see fleas”)
• Topicals (sprays, wipes, shampoos)
• Anti-inflammatory / anti-itch medication (short or long term)
• Treatment for skin infections and ear infections if present
• For some dogs: immunotherapy (allergen-specific desensitisation)
• Supplements to improve the skin barrier function (essential fatty acid (EFA) based supplements)

We often talk about an “itch threshold” in veterinary medicine. So some dogs may cope ok with their seasonal allergy if, for example, they also have a mild wheat allergy, which is managed through their diet. By not managing either, they can cross the threshold and become itchy.

If your dog needs long-term allergy medication, it’s normal to reassess periodically; the goal is usually to use the lowest effective dose that keeps them comfortable.

When to contact a vet urgently

Please seek urgent advice if you notice:

• Facial swelling, hives, breathing difficulty, or your dog collapsing
• Repeated vomiting, severe diarrhoea, or profound lethargy
• Painful ears, head tilt, or sudden intense discomfort

FAQs: seasonal allergies in dogs

About Dr Emma Pemberthy

Emma studied Natural Sciences at the University of Cambridge before retraining as a vet at the University of Nottingham. After nearly a decade in small-animal practice, she co-founded Petscribers to make access to pet medication more straightforward, affordable, and transparent for owners. She lives with her husband, two young sons, and a lively flock of call ducks.

Resources:

1. PDSA - Atopic dermatitis/skin allergies guidance (used for atopy basics, symptoms, secondary infections)
2. University of Surrey - Expert comment on seasonal allergies in dogs (used for how allergies show up in dogs and seasonal context)
3. Blue Cross - Food and skin allergies in dogs (used for general allergy overview, pollen/seasonality framing, and broader symptoms context)
4. UC Davis School of Veterinary Medicine - Dermatology fact sheets (used for flea allergy dermatitis details and “itch can persist after last bite”)
5. AAHA (American Animal Hospital Association) - Management of allergic skin diseases guidelines (used for diagnostic/treatment approach and allergy testing context)