Dog seasonal allergies (environmental allergies) can cause your dog to be miserably itchy and develop ear and skin infections too. Integrative veterinarian Dr. Julie Buzby discusses the causes, symptoms, diagnosis, treatment, and management of seasonal allergies in dogs to help your itchy pup get some much-needed relief.
Can dogs have seasonal allergies?
Yes, dogs can have seasonal allergies, but they look a bit different than allergies do for you and me.
Humans with seasonal allergies tend to have itchy watery eyes, a runny nose, and frequent sneezing. But dogs mostly have symptoms that center around their skin—seemingly constant itching, ear infections, and skin infections.
What are seasonal allergies in dogs?
Dog seasonal allergies, which are also known as environmental allergies or atopic dermatitis, occur when the dog’s immune system reacts to allergens in the environment. Dogs typically react to outdoor triggers like grasses, pollen, or weeds. But they can also have an allergic reaction to dust, dust mites, mold, and mildew indoors.
Because of the indoor allergens, “seasonal” allergies is actually a bit of a misnomer. They often become a year-round battle if the dog is allergic to indoor environmental allergens, or for particularly sensitive dogs in more temperate climates.
Typically, dogs start showing signs of seasonal allergies between one and three years of age, but it can be as early as six months or as late as six years. Additionally, if dogs move from one climate to another, they may develop seasonal allergies later in life due to new allergens in the environment.
What are the symptoms of dog seasonal allergies?
The most common allergy symptoms in affected dogs include:
Persistent itchiness (pruritis)
Dogs with seasonal allergies may be incessantly scratching, licking, and chewing the skin or itchy dog paws, and rubbing their face on flooring, bedding, or furniture. Sometimes they will have an area that seems itchier like their feet or face. Other times, it may look like every inch of your dog is itchy.
Hair loss (alopecia)
Hair loss in dogs may occur in the areas they scratch and chew most frequently. Pet parents may notice that their dog’s fur looks sparse and that many hair shafts appear broken off due to constant scratching or chewing at the skin.
Red skin (erythema)
Acute flare-ups of itchiness may cause the dog’s skin to be pinker or redder than normal. The muzzle, underarm areas (axillae), groin, feet, and toes are the most commonly affected areas in dogs with seasonal allergies. However, the dog’s entire body may be affected in severe cases.
Dark or black skin (hyperpigmentation)
Dogs who have been dealing with seasonal allergies for a while often have large, thickened areas of dark brown or black skin. This change in the skin occurs due to chronic inflammation, secondary bacterial or yeast infections, and the constant friction from scratching and chewing.
Salivary staining of the fur
A dog’s saliva turns the fur a rusty brown color. Thus, you may notice salivary staining on your dog’s coat secondary to excessive chewing and licking. It tends to be especially common on the legs, feet, genital area, and between the toes.
Scabs or pustules on the skin
Scratching, licking, and chewing can damage the skin’s protective barrier, opening the door for secondary yeast or bacterial skin infections (pyoderma in dogs). These infections may cause scabs, crusts, flaky circular areas on the skin (epidermal collarettes), pustules, or a rash on a dog’s stomach.
Hot spots
Hot spots in dogs may develop due to skin irritation from persistent chewing. This red, moist, painful area on the skin shows up quickly and can develop a secondary bacterial or yeast infection.
Ear infections
Ears are just an extension of the skin, so allergies can affect them too. Dogs with seasonal allergies may develop chronic or recurrent ear infections (otitis in dogs), with minimal downtime between episodes. The end result of the chronic infections can be thickening of the ear canals. This in turn predisposes the dog to future bouts of infection.
Facial irritation
Dogs often vigorously rub their faces on carpeting, furniture, or bedding if they cannot alleviate the itch with their paws.
Red, swollen, or watery eyes
Sometimes seasonal allergies can cause dogs to have eye symptoms that are similar to those in humans with seasonal allergies. The eye discharge is usually clear unless the dog develops a secondary infection, allergic conjunctivitis, or dry eye in dogs. In those situations, the dog may have cloudy, white, or yellow eye discharge.
Rhinitis and sinusitis
Dogs may develop inflammation of the nasal passages (rhinitis) or sinuses (sinusitis) as part of their allergic disease. Affected dogs have clear nasal discharge unless there is a secondary infection in the nasal passages.
Sneezing
Occasionally, dogs with seasonal allergies may have intermittent or paroxysmal sneezing. Or they may exhibit reverse sneezing in dogs.
When is allergy season for dogs?
Sometimes your dog’s allergies are most intense during a particular time of year such as spring or fall when levels of their particular outdoor allergen peak. However, indoor environmental allergens are present year round, so symptoms can be year round too. Or the dog can have year round allergy symptoms with seasonal worsening. So many options!
What causes seasonal allergies in dogs?
From a basic perspective, seasonal allergies develop due to environmental allergens that dogs inhale, ingest, or absorb through their skin. These allergens commonly include: tree, grass, and weed pollens.
It’s logical to think that seasonal allergies are triggered only by outdoor allergens. However, dogs may also develop a sensitivity to certain indoor allergens like mold, mildew, dust, dust mites, and dander that settle onto floors, furniture, and bedding.
There is more to it than simply exposure to allergens, though. Changes in the dog’s skin barrier function, gut health, and genetics may contribute to the development of seasonal allergies too. Let’s take a look at each one.
Defects in the dog’s skin barrier
When a dog’s epithelial barrier (the outermost layer of cells of the skin) is unhealthy, allergens, microbes, toxins, and even environmental pollutants are able to penetrate into deeper layers of the skin. Then the body will start to mount an immune response to the foreign invaders, leading to itching and inflammation.
When excessively licking or chewing the skin and fur, the dog may ingest some of these same allergens. This can lead to heightened immune responses in other body systems, including the GI and respiratory systems. As you can imagine, this can quickly become a vicious cycle of inflammation and discomfort for an allergic dog.
Changes in the bacterial populations in the dog’s gut
Interestingly, much research in human and veterinary medicine links the gut microbiome to skin health, commonly called the “gut-skin axis,.” A 2023 Cornell University study from the Department of Veterinary Medicine identified this disruption in normal gut microflora populations, called dysbiosis, in a group of dogs diagnosed with allergic dermatitis.
The affected dogs’ gastrointestinal microflora contained larger populations of abnormal bacteria than the study’s control group of dogs. Researchers also found that the severity of allergic dermatitis in dogs was directly related to the specific species of abnormal bacteria found in the highest populations in the gut.
Genetics
It is also important to note that seasonal allergies can be more common in certain dog breeds. This indicates that genetic predisposition may also play a role in environmental allergies in dogs.
The following dog breeds are more prone to seasonal allergies:
- Shiba Inus
- West Highland White Terriers (Westies)
- Golden Retrievers
- Labrador Retrievers
- Pit Bulls
- Scottish Terriers
- Fox Terriers
- Shar Peis
- Boxers
- Dalmatians
How will the vet diagnose a dog with seasonal allergies?
If your dog is itchy and has red, irritated skin and/or ears, or you are seeing other allergy symptoms, the best thing you can do is to schedule an appointment with your veterinarian. That way you can get to the bottom of problem and start getting your dog some relief.
The vet will diagnose a dog with seasonal allergies based on the history, exam, diagnostics, and ruling out other conditions that could cause itching.
Taking a history
During the visit, the vet will start by asking you questions about your dog’s history and symptoms. Sometimes knowing when the symptoms started, which areas of the body they are most prominent on, and if they seem to be worse at certain times of the year can help the vet start to distinguish between seasonal allergies and other types of allergies like food allergies in dogs or flea allergies in dogs.
Performing an examination
Then the vet will perform a nose-to-tail physical examination, paying special attention to your dog’s skin and ears. Your vet will look for signs of flea activity, as flea allergy dermatitis in dogs can also cause similar symptoms. Plus, the vet will take note of the severity of the skin inflammation and any signs of skin or ear infections.
Running additional diagnostics
To gather further information, the vet may recommend some of the following diagnostics:
- Skin cytology—Examining material from the surface of the skin under the microscope helps the vet look for evidence of yeast or bacterial populations that could contribute to your dog’s itching, body odor, and discomfort.
- Fungal culture—To rule out contagious fungal infections like ringworm, your veterinarian may run a fungal culture. He or she can collect the samples needed to run this test in-house. But it will take 10-14 days to get definitive results. If your vet has a high enough suspicion of a fungal infection, he or she may proactively prescribe antifungals while waiting for the test results.
- Ear swab cytology (and sometimes culture)— If the vet suspects an ear infection, he or she may examine the material in the ears under the microscope for yeast and bacteria. Depending on what he or she sees and/or your dog’s response to treatment, the vet may also recommend an ear culture and sensitivity to guide antibiotic selection. While obtaining a sample, your vet can assess your dog’s ears for narrowed canals or an eardrum defect. Both of these findings make an uncomplicated ear infection harder to treat.
- Skin biopsy—In severe cases the vet may lightly anesthetize your dog and collect several samples of skin. The biopsy samples will get sent to a veterinary pathology lab. There they will be examined under the microscope for the presence of resistant organisms or immune-mediated changes to the skin.
- Food trial—To rule out a food allergy in dogs who are itchy year round, your vet may have you feed your dog a hypoallergenic or novel protein/novel carbohydrate diet for 8-12 weeks.
What about allergy testing?
While it might sound like a way to diagnose seasonal allergies, vets actually use allergy testing to develop allergy shots (immunotherapy) and identify the primary allergens in dogs who have seasonal allergies. It is not intended to determine whether or not a dog has seasonal allergies because dogs with or without seasonal allergies can react to some of the allergens on the test.
Most general practitioners can collect the samples for blood testing for allergies. However, intradermal skin testing is generally administered and interpreted by a veterinary dermatologist. There are pros and cons to both types of allergy tests.
Don’t be fooled by at-home allergy test kits for dogs
You may have seen advertisements for easy at-home diagnostic test kits that analyze your dog’s allergic triggers using a saliva swab or a hair sample. Unfortunately, these kits are typically inaccurate (and expensive).
If you’re considering allergy testing your dog, working directly with your regular vet or a veterinary dermatologist is the best option. The allergy tests they perform provide reliable, accurate results. And they allow the veterinary team to make tailored treatment recommendations for your dog.
What is the treatment for seasonal allergies in dogs?
Once your vet diagnoses your dog with seasonal allergies, he or she will work with you to develop a treatment plan. Or in some situations your vet may facilitate a referral to a board certified veterinary dermatologist. Working with a veterinary specialist can be a great way to have access to intradermal testing or other advanced diagnostics. And he or she can help formulate a treatment plan for more complex cases.
Whether working with your family vet or a veterinary dermatologist, treating seasonal allergies often involves a multi-pronged approach. Some of the treatment and management options include:
Newer anti-itch medications: Apoquel or Cytopoint
Prescription allergy medicine for dogs such as Apoquel® (daily or twice daily oral tablet) and Cytopoint® (injection that lasts 4-8 weeks) can help quickly alleviate your dog’s itching. Both medications target the molecules that cause itchiness, but they do it in different ways. Apoquel also has some mild anti-inflammatory properties, but Cytopoint does not.
Keep in mind though that these medications don’t treat the underlying cause(s) of allergies. Their purpose is to relieve itching while you and your veterinarian work on other aspects of allergy control.
Steroids
If your dog is dealing with severe itching and inflammation, your vet may prescribe a short “crisis buster” course of oral steroids for quick relief. Steroids are inexpensive and highly effective for short-term control of allergic itch. But they should not be used at high doses for prolonged periods due to potential adverse side effects.
Prednisone for dogs, prednisolone, hydrocortisone (usually in topical products), and Temaril-P® are the most commonly used steroids for allergies in dogs. Additionally, vets sometimes also administer long-lasting steroid injections (methylprednisolone or triamcinolone) in certain situations.
Topical products
Since allergens enter through the skin and most of the symptoms involve the skin, topical therapy is often very helpful for dogs. Some possible options include:
- Topical fatty acid supplements to support the skin barrier
- Medicated shampoos, sprays, mousses, or wipes that contain antifungal, antibacterial, or anti-itch ingredients and/or are good for cleansing, supporting, and soothing the skin
- Baby wipes or specialized wipes to remove allergens on paws after outdoor activities or to address dog paw yeast infections
- Prescription ear cleaners for regular ear cleansing (For tips, check out my article, How to Clean a Dog’s Ears in 10 Simple Steps.)
Antihistamines
Many common OTC human antihistamines such as Benadryl for dogs, hydroxyzine, chlorpheniramine, Zyrtec® (cetirizine), or Claritin® (loratadine) are generally safe to administer to your dog under the direction of your veterinarian. They may be effective for mild cases of seasonal allergies. But they aren’t going to make a significant difference in moderate to severe allergy symptoms.
Additionally, it is important to ensure that you do not give your dog antihistamines that are combined with other medications. For example, the decongestant pseudoephedrine in Claritin-D® is dangerous for dogs.
Immunotherapy (allergy shots)
The gold standard treatment for seasonal allergies in dogs is allergen specific immunotherapy (ASIT). It is available as allergy shots (injections) or in a sublingual (under the tongue) form. ASIT is customized for the dog based on the results of the intradermal or blood allergy testing. The goal is to expose the dog’s immune system to small amounts of allergens at a time so that it becomes desensitized.
Generally, it can take months to see improvement. Thus, the dog will need other therapies to manage allergy symptoms while waiting for the ASIT to take effect. Also, between 50 and 80% of dogs will respond after a year of therapy, so it isn’t a sure thing. Immunotherapy can also get expensive and not all dogs tolerate it well.
On the other hand, ASIT does have the potential to result in a cure in some cases. And it is the only therapy that addresses the root of the problem (the immune reaction).
Oral supplements
Prebiotics/probiotics, colostrum, and medicinal mushrooms for gut and immune support are just a few of the integrative therapies that can be helpful for dogs with allergies. These products can be used safely in conjunction with prescription medications and special diets under the direction of your veterinarian.
However, keep in mind that these natural remedies for seasonal allergies aren’t necessarily going to be strong enough to tackle the dog’s symptoms on their own. Rather, they are part of the plan.
Management of secondary infections
If the dog has skin or ear infections, it is important to address them too. Infections can contribute to the itching and discomfort the dog is experiencing. For ear infections, the vet will typically prescribe an ear medication containing an antifungal, antibiotic, and anti-inflammatory (usually a steroid). Systemic and/or topical antibiotics and antifungals are the treatment of choice for skin infections.
Veterinarian-prescribed flea control
Many dogs who have seasonal allergies also have an allergy to flea saliva. Thus, it is important to keep them on a veterinarian-prescribed flea preventive year round. Plus, all other pets in the household should be on a flea preventive year round. This helps reduce flea bites, which can add to the itching a dog is already experiencing due to seasonal allergies.
Please avoid using over-the-counter flea control preventives. While less expensive than the products you buy from the veterinarian, they are also less effective. And sometimes they are even dangerous.
Allergen reduction in the home
It can be helpful to use air purifiers or HEPA filters with HVAC systems to filter allergens out of the indoor environment. Additionally, you should dust, vacuum, or deploy a Roomba regularly to avoid accumulating potential allergic triggers on hard surface floors, carpeting, and bedding.
What is the prognosis for dogs with seasonal allergies?
Typically, you and your vet can find a combination of the therapies listed above that can manage your dog’s seasonal allergies. However, it is important to keep in mind that the vast majority of the time, seasonal allergies aren’t something that is cured. Rather the goal is to decrease the number and severity of the flares and keep your dog as comfortable as possible.
How easy this is to do depends on the individual dog and his or her immune response to allergens. Overall though, the prognosis for dogs with seasonal allergies is good with appropriate management, but unmanaged allergies can be quite miserable for dogs.
How can you prevent dog seasonal allergy flare ups?
You’ve probably heard the old saying, “An ounce of prevention is worth a pound of cure.” In the battle against seasonal allergies, this is certainly a valid statement! The following six tips are things you can do at home to help decrease the chances or severity of seasonal allergy flare ups.
1. Discuss skin and coat or immune support supplements with your vet
Because the gut, the skin barrier, and the immune system play such a big role in allergies, supporting those systems is important. And it becomes even more critical if your dog is sick or has medical conditions that may compromise the immune system. Your vet can help you find the skin, coat, or immune support supplements that are right for your dog.
2. Regularly clean your dog’s feet, ears, and coat
Regular baths will keep the skin and coat clean, soothe the skin, and minimize allergens carried into the home from outside. Plus, wiping your dog’s feet after coming in from outside can help remove allergens and irritating debris or dirt. And keeping your dog’s ears clean will decrease the chances of an ear infection.
3. Be proactive rather than reactive
I like to tell my clients to take action at the first signs of allergies, or even before. If you know your dog’s seasonal allergies usually kick off in late May, then begin bathing, ear cleaning, foot wiping, etc. at the start of May. Don’t wait until the allergy ball has already started rolling down the hill!
Along the same lines, it is important to seek veterinary care for your dog sooner rather than later once allergies flare up. Proactive treatment for allergy symptoms and secondary infections can significantly reduce the time to resolution. Conversely, waiting to see if the symptoms will get better on their own often backfires, leaving your dog uncomfortable and itchy for longer than necessary.
4. Keep the home clean and minimize allergens
Wipe down floors and baseboards, vacuum or wipe down furniture, and launder your dog’s bedding in hypoallergenic laundry soap to keep the indoor environment as allergen-free as possible. Also, avoid heavily scented perfumes, candles, oil diffusers, or air fresheners to minimize inhaled allergic triggers.
5. Keep your dog on flea control year round
Even in climates with cold winter months, fleas (and ticks) can be hardy little creatures. So the importance of flea preventives cannot be stressed enough. If your dog is one of the many dogs who have flea allergies and seasonal allergies, one flea bite can make him or her itchy and miserable. This itching layers on top of the itching that is coming from seasonal allergies, making the dog even more uncomfortable.
6. Keep track of your dog’s symptoms and response to treatment
It can be helpful to take photos of your dog’s skin and coat on a weekly basis (or sometimes even more often). This allows you to document changes in the size, appearance, or severity of skin or ear abnormalities. When you take the picture, also score your dog’s itchiness on a scale of 1 to 10, with 1 being not itchy and 10 being severely itchy. Then note what approaches you are currently using to manage the allergies.
All this information will come in handy when you and your vet are trying to figure out what works or doesn’t work for your dog.
Be patient and partner with your vet
Seasonal allergies can be one of the more frustrating diagnoses. It often takes trial and error to find a combination of medications and management strategies that work for your dog. Plus, since allergies tend to worsen as a dog gets older, you may need to modify your approach from year to year.
Your vet understands this struggle and wants to do everything he or she can to give your dog relief from allergy symptoms too. By working together, hopefully you can find the right solutions for your dog. Then you no longer need to dread allergy season and your dog doesn’t have to spend part of the year (or more) with severely itchy irritated skin. It’s going to take some time and patience, but it is possible!
Does your dog have seasonal allergies?
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