Allergies in Dogs: Symptoms, Causes, and Treatment

Does your dog scratch, chew, or lick themselves excessively? If so, they may have allergies. 

Allergies in dogs most commonly cause itchy skin, ear infections, and paw licking, and they’re usually triggered by environmental allergens (like pollen), fleas, or certain foods.  

Treatment of dog allergies depends on the cause and often requires veterinary diagnosis and long-term management.  

Can Dogs Have Allergies?

Yes, dogs can have allergies. In fact, allergies in dogs are one of the most common reasons for veterinary visits. 

What Are Allergies in Dogs?

Dogs with allergies have a hypersensitive immune system that gets triggered by certain substances (allergens). In dogs, allergies typically affect the skin and ears, rather than causing the respiratory symptoms commonly seen in people. Dogs with allergies often develop secondary bacterial or yeast infections from scratching. 

Dog Allergy Symptoms

Symptoms will vary depending on the type of allergy your dog has, but may include: 

• Itchy skin 

• Excessive scratching or licking 

• Face rubbing on floors or furniture 

• Red or inflamed skin 

• Hair loss 

• Recurrent skin or ear infections 

• Gastrointestinal issues (vomiting or loose stools) specific to food allergy 

Types of Allergies in Dogs

There are several types of allergies in dogs. Below, we’ll take a closer look at each type of allergy in dogs and how it affects your pet. 

Environmental Allergies 

Environmental allergies, also known as atopic dermatitis, are caused by substances that exist in your home, backyard, and anywhere else your dog spends time. 

Common triggers for these allergic reactions include: 

• Pollens 

• Plant or animal fibers 

• Dust mites 

• Mold spores 

These allergens can be inhaled, as with pollen, or absorbed through the skin when your dog touches them.  

When environmental allergies occur seasonally, they are known as seasonal allergies. Other environmental allergies, like allergies to dust mites, may occur year-round. 

Flea Allergies 

An allergy to fleas, called flea allergy dermatitis, is the most common skin disease in dogs. 

The bite of just one or two fleas is enough to make affected dogs itch. Proteins in flea saliva are believed to be the allergens that cause the itchiness. 

With flea allergies, you may or may not see live fleas on your dog. You may also notice black dots that look like coffee grounds at the base of your dog’s fur. These black dots are flea dirt, or flea excrement, and contain digested blood. 

Food Allergies 

Dogs can develop an allergy to a particular food at any age. 

Most commonly, the allergy is to a specific protein in the food, like chicken or beef. While allergies to grains or other ingredients can occur, they aren’t common. 

Dog Allergy Treatment

Treatment for allergies in dogs depends on the underlying cause. Your veterinarian may recommend anti-itch medications, flea medication, medicated baths, immunotherapy, or a prescription diet. Below are examples of how treatment varies based on the type of allergy. 

Treatment for Environmental Allergies in Dogs 

Treatments for environmental/seasonal allergies in dogs can include: 

• Anti-itch medications: Your vet may prescribe oral or injectable medications to alleviate itchiness and manage itching during flare-ups. One such medication is Zenrelia, which is a once-daily oral tablet designed specifically to control allergic itch in dogs over 12 months of age.  

• Steroids: Steroids help reduce inflammation that drives itching but are not recommended for long-term use due to potential side effects. 

• Medications to treat infections: Your vet may prescribe ear drops for bacterial or yeast ear infections, an antibiotic injection (Convenia) or oral antibiotics for bacterial skin infections, or antifungal medications for yeast infections. 

• Immunotherapy: Customized allergy shots or oral drops formulated from allergy testing results may help gradually desensitize a dog to allergens over time.  

• Supportive home care: Medicated baths, topical products (sprays, wipes, or mousse), and omega-3 fatty acid supplements may help soothe irritated skin and support skin health. 

If an allergy test has been performed, then the ideal allergy treatment for dogs is avoidance of the allergen. This is possible in a few, select circumstances, but most dogs are allergic to a variety of substances that can be difficult to avoid completely. 

Treatment for Flea Allergies 

Treatment for flea allergy dermatitis in dogs is twofold:  

• Getting rid of the fleas 

• Reducing the symptoms of itchy skin and irritation until the fleas are gone  

To eliminate fleas, strict flea control is required. There are many highly effective flea control products and medications available, ranging from topical spot-on treatments, such as Revolution or Bravecto, to oral pills and chews, such as Credelio Quattro. If your dog needs rapid relief from live fleas, Capstar (nitenpyram), which starts working in 30 minutes, may be recommended. 

Consult with your veterinarian to determine your best option for your pup and their individual symptoms. Other animals in the home should also be treated for fleas. 

In severe cases, a dog’s environment must be treated for fleas as well. Vacuum thoroughly to remove adult fleas, flea eggs, larvae, and pupae, and discard the vacuum bag immediately. Use insecticides that contain an insect growth regulator to treat all flea life stages inside and outside your home.

Anti-itch medications, either in an oral tablet or injection form, can provide symptomatic relief until the fleas are gone.  

Treatment for Food Allergies 

To diagnose a food allergy in dogs, a hypoallergenic dog food is recommended for eight to 12 weeks. 

During the feeding trial, dogs can't eat any other foods, including treats, human foods, or flavored medicines. This is the only way to determine if your dog has a food allergy.  

Hypoallergenic diets either have limited ingredients with an uncommon protein source or are processed in a special way (hydrolyzed) to be less likely to cause allergic reactions. The concept is that a dog can’t be allergic to a food that they have not been exposed to before. 

Over-the-counter foods are not recommended for a proper food trial. Consult your veterinarian when choosing the proper veterinary diet. 

If it’s determined that your pet has a food allergy, your veterinarian may recommend keeping your dog on the allergy diet long term.  

Other allergy treatments for dogs can be helpful when reducing the symptoms while waiting to see if the diet change is helpful. However, use of certain medications can interfere with food trials—it can be difficult to determine if improvement is due to the food or the medication. Always consult with your vet before giving your pup any medication.