What Causes Dog Allergies? 5 Common Triggers in Your Home

Dog allergies are more common than people realize. And they’re not always caused by pollen floating through the air. In many cases, the problem is right inside your home. Dust mites, cleaning products, and even your dog’s bed could be triggering a reaction.

The tricky part? Allergies in dogs don’t always look the way they do in humans. Instead of sneezing fits, they often show up as itchy skin, ear infections, or constant paw licking. It’s easy to mistake them for something else.

That’s why understanding the most common household allergens is important. Because no one wants to see their dog uncomfortable.

1. Dust Mites

You can’t see them, but they’re there.

Dust mites are tiny creatures that survive by eating dead skin cells—both human and pet dander. Think of them as uninvited house guests that never leave.

Related: How to Use an Air Purifier for Dog Hair and Dander

They don’t bite, sting, or burrow. But, their droppings contain proteins that can trigger allergic reactions in dogs. And because they live in soft fabrics—like carpets, bedding, and upholstered furniture—it’s easy for dogs to come into contact with them.

The warmer and more humid your home is, the better the conditions are for dust mites to multiply. And the more of them there are, the more allergens your dog is exposed to.

Signs Your Dog Might Be Allergic to Dust Mites

• Non-stop scratching (especially at night when mites are more active).
• Licking or chewing their paws—a big red flag.
• Red, irritated skin, particularly on the belly, armpits, and around the eyes.
• Frequent ear infections or wax buildup.
• Sneezing or “reverse sneezing” (a loud snorting sound, usually triggered by irritation in the nasal passages).

2. Household Cleaners

Cleaning your home should make it safer and healthier—not turn it into an allergy zone. But for dogs with sensitivities, the very cleaning products meant to keep things fresh could be making them uncomfortable.

Harsh chemicals don’t just disappear after you spray and wipe. Residue lingers on floors, carpets, and furniture. If your puppy likes to sprawl out on the floor or lick their paws, they’re coming into direct contact with those leftover irritants.

And it’s not just industrial-strength cleaners that can cause problems. Even some “natural” cleaning products—especially those with strong fragrances or essential oils—can trigger allergic reactions.

That's why you need to always check the ingredients used for your fabric cleaners. Check out ALZOO Enzyme-Based Stain & Odor Remover.

If your dog has been itching more than usual or avoiding rooms right after you clean, your household products could be to blame.

Here are a few of the biggest culprits:

• Ammonia and bleach – Found in many disinfectants, these chemicals can irritate a dog’s nose, throat, and lungs.
• Artificial fragrances – Scented sprays, air fresheners, and cleaners often contain synthetic chemicals that can trigger allergies.
• Essential oils – Some natural products use oils like tea tree, eucalyptus, and citrus, which can be irritating—or even toxic—to dogs.
• Residue buildup – Even if a cleaner seems mild, leftover residue on floors, carpets, and furniture can cause skin irritation.

Signs Your Dog Might Be Reacting to Cleaning Products

• Coughing, sneezing, or watery eyes – Especially after being in a freshly cleaned space.
• Red, irritated skin or excessive itching – If your dog lies on the floor and then starts scratching, that’s a clue.
• Avoidance behavior – Does your dog refuse to enter a room right after you’ve mopped or sprayed furniture? They might be reacting to the fumes.

3. Mold & Mildew

Mold isn’t just an eyesore—it’s a problem that can sneak up on you. It hides in damp corners, spreads quietly, and releases tiny spores into the air.

For dogs with allergies, these spores can trigger constant itching and respiratory trouble. The tricky part? Mold isn’t always obvious. It can grow behind walls, under sinks, and even in your dog’s water bowl.

If your pet has persistent allergy symptoms that don’t seem tied to the usual suspects (like pollen or dust mites), mold could be the hidden culprit.

Signs Your Dog Might Be Allergic to Mold

• Coughing or wheezing – if your dog sounds congested or struggles to breathe after spending time in a certain room.
• Skin problems – itching, rashes, or unexplained hair loss.
• Recurring ear infections – especially if they seem to clear up and come right back.

4. Pollen & Outdoor Allergens

You might think pollen is only a problem for humans. But dogs can suffer from seasonal allergies, too.

The tricky part? Even if your dog spends most of their time indoors, pollen and other outdoor allergens still find a way inside. And once they do, they settle into carpets, furniture, and bedding—places your dog comes into contact with daily.

Signs Your Dog Is Reacting to Outdoor Allergens

• Excessive paw licking or chewing – Pollen on their paws can cause irritation, leading to nonstop licking.
• Red, watery eyes and sneezing – Just like humans, dogs can get teary-eyed and sniffly from pollen exposure.
• Skin flare-ups – If your puppy develops red, itchy patches or rashes during certain times of the year, outdoor allergens might be to blame.

5. Food Sensitivities

It’s easy to assume that if a dog has a food allergy, they’ll have stomach issues. But in reality, most food allergies in dogs show up as itchy skin, ear infections, and paw irritation—not vomiting or diarrhea.

Unlike environmental allergies, which fluctuate with the seasons, pet food allergies cause year-round symptoms.

And since dog food allergens enter the bloodstream, they often cause skin reactions rather than immediate digestive distress.

Signs of a Food Allergy in Dogs

• Chronic itching – Especially around the ears, paws, and belly.
• Recurring ear infections – If ear infections keep coming back despite treatment, diet could be a factor.
• Scooting or licking the rear end excessively – It’s awkward, but an itchy rear is a common sign of food allergies.
• Red, inflamed paws or hot spots – Constant licking or chewing can indicate irritation caused by an allergic reaction.

How to Identify & Manage Food Allergies

• Try an elimination diet – Feed your dog a single-protein, limited-ingredient diet for 8-12 weeks (under vet supervision) and see if symptoms improve.
• Switch to hypoallergenic dog food – These formulas use hydrolyzed proteins or novel proteins (like duck or venison) that are less likely to cause a reaction.
• Avoid common allergen treats – Many dog biscuits, flavored chews, and dairy-based treats contain ingredients that could trigger symptoms.

Once you figure out the culprit, managing food allergies is straightforward—remove the problem ingredient, and your dog’s symptoms should improve. If symptoms still persist, go to your veterinarian for a check-up.

So, What Now? A Few Simple Changes Can Help

Dog allergies can be frustrating—for both you and your beloved dog. But now you know the most common culprits hiding in your home: dust mites, cleaning products, mold, pollen, and pet food sensitivities.

The good news? In many cases, small changes can make a big difference. Regular cleaning, swapping out harsh chemicals, controlling humidity, and monitoring your dog’s diet can help reduce allergens and ease their discomfort.

If symptoms persist, start tracking patterns. Do flare-ups happen after meals? After walks? In certain rooms? Noticing these trends can help you pinpoint the problem and make your vet’s job easier if professional help is needed.