Resource Center Menu

Help Fix Your Dog's Seasonal, Environmental & Food-Based Allergies

Dog Allergies-Symptoms, Testing and Treatment

Does your dog seem itchy and uncomfortable? Do they have stomach or skin problems you can’t figure out? Dog allergies could be the cause.  

 Allergies are one of the most common health conditions in dogs and can be a lifelong battle. But with the correct information and strategies, you can help fix your dog’s itchy skin and other issues and get them on the path to good overall health.

What Are The Most Common Dog Allergies?

There are three main categories of dog allergies—food and medication, environmental and seasonal—and within each category, there are some allergens that are more common culprits than others.  

  Food and medication dog allergies 

  Allergies to certain foods are one of the most common types of allergies in dogs. Dogs can be born with these allergies or develop them over time, so keep in mind that food could be the culprit at any stage of your dog’s life. The most common dog food allergy is chicken or other popular proteins like beef and pork. Eggs and dairy, and wheat, corn and soy, are also behind many food allergies. Dog food for allergies often helps eliminate these ingredients. 

  Like people, dogs can also be allergic to medications. Steroids, antibiotics like penicillin and NSAIDs like carprofen can sometimes cause reactions. Dog allergies to medications are rare but can come on quickly, so always keep an eye on your dog after giving a new drug. 

  Environmental dog allergies 

  This type of dog allergy is caused by particles in the air in your home or the surrounding area and can have natural or man-made causes. Natural environmental allergens are things like mold spores, dander, dust mites and fleas. Allergens that humans could be bringing into your home may include cigarette smoke, cleaning products—including any detergent you use to wash your dog’s bedding—and down feathers and perfumes.  

  Seasonal dog allergies 

  Seasonal allergies can also be considered environmental, but as in humans, this type of allergy will typically only come around once or twice a year. The season and severity of this type of dog allergy will usually vary depending on where you live, but spring and fall are the most likely seasons because your dog’s seasonal allergies may be caused by weeds, grasses and pollen. 

How Can You Tell If A Dog Has Allergies?

The symptoms of dog allergies vary depending on the type of allergen. However, there are few common signs to look for. Generally, a dog with itchy skin or ongoing gastrointestinal problems may have allergies. 

 Skin symptoms 

 Is your pup constantly scratching, rolling on the carpet or biting at their paws and tail? That’s a dog with itchy skin—and it may be a tell-tale sign of allergies. Even if you don’t see anything else wrong, you’ll want to consult a veterinarian. Scratching and biting can easily escalate into missing fur and abrasions. More visible signs of dog skin problems include inflammation and redness, hives and other bumps and chronic ear infections.   

 Stomach, eye and ear symptoms 

 Gastrointestinal symptoms like diarrhea and vomiting often indicate food allergies or sensitivities. These symptoms are never fun, especially for your dog, so you’ll want to get them sorted out as soon as you can.  

 Itchy, watery eyes, a runny nose, coughing or sneezing are often indicators of environmental dog allergies. If it happens only in the spring or fall, it’s likely seasonal allergies that react to pollen, grass or weeds. At other times of the year or year-round, it could indicate it’s a reaction to something in your home or neighborhood. 

 Acute symptoms 

 Acute dog allergy symptoms are an immediate reaction to something your dog has ingested or inhaled and often manifests as facial swelling, including the lips, eyelids and ears. They can be environmental or due to something your dog has eaten. As in humans, common causes are bee stings, vaccines and foods. And like humans, dogs can go into anaphylactic shock, so if your dog is having difficulty breathing or swallowing, get them to a veterinarian.

How Are Dog Allergies Diagnosed?

Diagnosing dog allergies can be a real pain in the tail. Unless your pup had an evident and immediate adverse reaction to something, the specific underlying causes of allergies can often be a bit of a mystery. Here are a few things your veterinarian might try. 

 Dog allergy testing 

 Testing is often the easiest and fastest way to diagnose dog allergies. It can help detect many food and environmental allergies, but it can still miss things if it does not test for them, so the more comprehensive the test, the better.  

 Dog allergy testing can be done in several ways. Intradermal testing involves injecting small doses of allergens into the skin to look for reactions. Serum testing requires blood samples. There are also at-home tests that use saliva or fur—which may not be as reliable, but can be a good option for minor allergies. 

 Elimination diets 

 For suspected food allergies with more mild symptoms, you can try an elimination diet before you jump right to testing. In an elimination diet, you’ll feed your dog only one source of protein at a time. The diet is ideally home-cooked or prescription so you can carefully monitor ingredients. 

 Dog food for allergies is made of uncommon protein sources, like lamb, venison, rabbit, duck or fish. Choose one your dog hasn’t had and feed them only that protein for 8 to 12 weeks—no human food, supplements, rawhide, bones or other treats can be given. If allergy symptoms appear, you’ll have determined one of the causes of the allergy. If there’s no allergic reaction, choose another protein to test. Before long, you’ll have a list of foods your dog can eat.  

 Visual diagnosis 

 There is one type of allergy that’s relatively easy to diagnose. Dog itchy skin can be a sign of flea allergy dermatitis, an overreaction to flea bites. It often results in severe itchiness and hair loss and is most common in dogs between ages three and five. The good news is that your veterinarian can usually diagnose this type of allergy by looking for fleas or evidence of fleas, saving you the time and cost of dog allergy testing.

How Are Dog Allergies Treated?

Diagnosing allergies is the hard part. Once you know what’s causing the reaction, treating dog allergies may be relatively easy. For acute allergic reactions, emergency care is always the best course of treatment.

 Over-the-counter treatments 

 You want to relieve your dog’s discomfort as soon as possible—so what can you give a dog with allergies? You can help alleviate your dog’s itchy skin and other symptoms with the right over-the-counter allergy products like shampoos, coat and skin sprays and supplements like fish oil may help your dog be more comfortable as you figure out what’s going on. Benadryl (diphenhydramine) can also sometimes be used for dogs but ask your veterinarian about proper dosing.  

Limited exposure

 Once you know the specific cause, food, medication and environmental dog allergies usually have a simple solution: Stop exposing your dog to that allergen. Dog food for allergies can limit the number of ingredients you’re feeding your dog and help you avoid food triggers. Hypoallergenic dog beds can help with environmental factors, in addition to eliminating the allergen from your home.  

 Allergy medications 

Allergy relief prescriptions may be appropriate for more severe allergies or those that can’t be avoided, like seasonal allergies. They usually include antihistamines, given as a nasal spray or tablets, corticosteroids, which are typically nasal sprays and leukotriene modifiers, administered if the first options aren’t effective.  

 Immunotherapy can also be available for dog allergies, just like humans. Small doses of the allergen are given over four to six months, “training” the immune system not to respond to the allergen. Immunotherapy can be expensive but may be worth it for severe allergies.  


 Flea allergy dermatitis is the only dog allergy that can be managed with preventive treatments. Flea and tick treatment can help prevent this reaction and help prevent serious diseases like tapeworms, Lyme disease, ehrlichiosis and Rocky Mountain spotted fever.  

 Flea prevention for dogs is an essential part of any dog health care routine—but what is the most effective flea treatment for dogs? There are a lot of options, including tablets given orally, topical treatments and collars. Collars can be an economical choice but may not be as effective as oral or topical treatments. Chewable tablets are quickly becoming one of the most popular choices thanks to their reported effectiveness and ease of use.  

 Dog allergies can be frustrating—for you and your dog. Dogs with itchy skin just can’t seem to stop scratching. Gastrointestinal problems can be messy and uncomfortable. And no one likes to see their best friend in discomfort. But there is help out there for dedicated dog parents. Armed with the latest information about the symptoms, causes, testing and treatments for dog allergies, you’re ready to tackle this problem with confidence.

Reviewed by Petco’s Animal Care, Education and Compliance (ACE) Team

Petco’s ACE team is a passionate group of experienced pet care experts dedicated to supporting the overall health & wellness of pets. The ACE team works to develop animal care operations and standards across the organization and promote proper animal care and education for Pet Care Center partners and pet parents, while also ensuring regulatory compliance.