What Causes Dog Allergies?

You’re beginning to worry about your four-legged companion. He’s not acting like his normal, happy self. You’ve noticed that he’s scratching himself a lot, sneezing, and has even thrown up a few times after eating. A number of different issues could be at play, but you suspect that something is triggering his problems. If you have questioned, “Can dogs get allergies?”, you are not alone.  

Though you’d love to help your pup feel happy and healthy once again, you aren’t exactly sure what’s causing these dog allergy symptoms to occur. If you only knew what was triggering such a bad allergic reaction, you could then take your dog to the veterinarian to ensure he’s getting the treatment he deserves.

Before learning about what causes dog allergies, let’s take a look at what allergies are and how they may affect your pup.

Dog Allergies 101

Just like humans, dogs suffer from many different types of allergies, which are an immune system reaction, according to The Spruce Pets. When your dog’s body comes into contact with food or environmental allergens, it will start producing antibodies, which are cells that safeguard the body from bacteria and viruses, or foreign invaders. White blood cells will sometimes process things that are harmless, like dust, food proteins and fleabites, as harmful. Once the white blood cells begin to fight back, that’s when the symptoms of allergies will develop

All different dog breeds and dogs of various ages can get allergies. Allergies can be an ongoing problem throughout a dog’s life or just occur when they have eaten something that doesn’t react well with their system, they are in a new environment, the season has changed or there is an allergen in the air. 

Now that you know about dog allergies, it’s time to discover what causes them. 

What Causes Allergies in Dogs?

There are four things that can cause dogs to have an allergic reaction. They are: 

  • Food
  • The environment (inside and outside)
  • Parasites and fleas
  • Contact

When discussing what causes pet allergies, it’s helpful to know the symptoms of each to determine which one your pup is experiencing.

Food Allergies

According to Metropolitan Veterinary Center, if your dog is excessively licking his feet, is scratching himself, has gastritis, is throwing, has diarrhea, has an ear infection, or inflammation, he may be having an allergic reaction to food. A dog food allergy develops over time, and are caused by the body not being able to break down proteins or other ingredients. 

If your dog eats the same thing every day throughout his life, a food allergy is likely to develop. According to Nom Nom Now, the protein, like meat, dairy and eggs can trigger, “an adverse immune response, which then causes cells in the body to release histamines, or compounds that lead to itching and many other allergic signs.” Even if your pup has diarrhea or shows other signs of a food allergy, it could just be a food intolerance, which is much more common. Studies show that more than a third of dogs that have one food allergy will be allergic to at least one more type of food as well. 

Environmental Allergies

If your dog is sneezing, has lesions on his feet, has a runny nose or is coughing, he may be experiencing an allergic reaction to the environment, according to petMD. Your dog may have seasonal allergies; for instance, in the springtime, he may start sneezing because he’s allergic to pollen or dander. However, if you live somewhere warm year-round like Hawaii or Los Angeles, your pup may have allergies all the time. Older dogs are more prone to seasonal allergies to things like pollen, grass, or dander

Inside environments can also cause your dog to have an allergic reaction. For instance, if you go to The Home Depot and there is a lot of dust from the wood saw, your dog could start sneezing. Maybe your home is dusty or you’re using a certain cleaner that he doesn’t react well to. You could have mold throughout your home, and this is making your dog sick. Allergens inside your home can be a big problem since your dog spends so much time there. It’s important to pinpoint exactly what could be causing the issue before you can start treating your dog for allergies.

Parasites and Fleas Allergies 

Fleas are, unfortunately, a fact of life for dogs. Fleas are especially prevalent in the warmer months, where they breed more in your yard and in your home. Dogs with allergic reactions to these parasites have what’s called flea allergy dermatitis, according to Pet Health Network. 

When a flea bites your dog, the saliva gets onto your dog’s skin and causes a reaction. The skin will become extremely itchy and may even put your dog at risk for other skin infections. If your dog scratches too much, for instance, he could experience hair loss or develop skin lesions. Your pup may also have a flea allergy if he is biting and scratching different areas of his body. 

Dust mites and ticks can also get onto your dog’s skin and cause it to flare up. While ticks are easy to spot, you won’t be able to see the dust mites on your dog. According to VCA Hospitals, some sensitive pups will also have allergic reactions to insects like spiders, wasps, hornets, deerflies, horseflies, ants, mosquitoes and bees. 

Contact Allergies

Contact skin allergies, also known as contact dermatitis, can occur when a dog brushes up against an allergen and causes a reaction. According to petMD, salt put down on the road after a snowstorm or plants like poison ivy can cause your dog to develop a skin rash upon contact. Contact skin allergies can occur at any time and any age, but the breeds that are most at risk of having these allergic reactions include Scottish Terriers, French Poodles, German Shepherds, Golden Retrievers and West Highland White Terriers. 

Along with plants and salt, other things that can irritate your dog’s skin include mulch and cedar chips, fertilizers, plastics, fabrics, rugs, carpets, concrete, soaps, floor waxes, carpet and litter deodorizer, rough surfaces, topical agents, sensitivity to heat or the sun, rubber, leather, and herbicides. Since all these things could lead to an allergic reaction, it could be hard to determine exactly what’s causing the problem. 

Testing and Treating Your Dog’s Allergies 

You may have seen the above symptoms manifest in your dog, but how do you know exactly what’s causing the underlying problem? You’ll need to take a trip to the veterinarian to see what the issue is and how to solve it. 

Your vet is going to run some allergy tests to figure out what’s happening. According to the Drake Center, there are two kinds of allergy testing: intradermal skin tests and blood tests. 

With intradermal skin testing, your veterinarian will shave part of your dog’s hair on the side of his body and inject various allergens into your dog to see which one he reacts to. Even though your dog is being injected with the allergens themselves, your veterinarian is there to treat him immediately if there is a bad reaction. 

If your vet doesn’t do the intradermal skin testing, they may run a blood test instead. This would involve taking a sample of your dog’s blood and sending it to a lab. Once the results come back, your vet will be able to recommend a course of treatment. 

Depending on what allergy your dog has, there are various ways to treat it. If it’s a contact allergy, then you will have to figure out what is causing the reaction and then remove that trigger from your dog’s environment. For example, you may have to switch out your dog’s bedding or not go to a certain park if there is poison ivy amongst the bushes. If your dog accidentally brushes up against something anyway, you can always use coconut oil or a soothing dog shampoo to repair his skin.

If it’s a food allergy, your veterinarian will put your dog on an elimination diet for his food, treats and supplements. Then, once you see what the problem is, you’ll need to switch out his dog food for a brand that is more gentle and compatible to your dog’s system. 

If it’s an environmental allergy, you can treat your dog by giving him Benadryl or Zytrec (speak to your vet to find out the appropriate dosage) or a medicine that your vet prescribes to you. It’s also important to keep your house clean by washing dog bedding and your own bedding once a week if your dog sleeps with you.  Vacuum and dust frequently, and invest in an air purifier to rid the area of dust. If your dog is allergic to cleaners, then make your own out of white distilled vinegar, lemon juice and baking soda.

If your dog is allergic to fleas, make sure you buy a flea medicine, give him a flea bath regularly, and avoid areas like forests and dense foliage where fleas and insects like to hide. After every outing, make sure to do a brief check for tick son your dog’s skin.

With a little bit of help from your vet and some due diligence on your part, you can ensure your pup’s allergic reactions are controlled and he is comfortable and happy throughout his life. If you’re looking for a pet allergy treatment, Pet Honesty has a variety of effective options to give your pup. Whether you go for canine allergy relief chews or our famous skin health chews, our online selection has a number of powerful pet supplements to keep your dog healthy and happy for years to come. 












Camille Arneberg, Co-Founder of PetHonestyCamille is a co-founder of PetHonesty and VP of Pup Parent Education. After watching her own family dog suffer from joint issues for years she became passionate about improving dogs’ quality of life. With the help of a team of veterinarians and dog nutritionists she now helps educate other dog owners about the small but powerful things they can do to positively impact their dogs’ health and wellness! She lives in Austin, TX and loves cuddling puppies, being outside and reading.