Dog Skin Allergies: Causes, Symptoms, and Treatment

By Georgina Ushi, DVM. Reviewed by Barri J. Morrison, DVM

Updated Apr. 9, 2025

Dog itching and chewing self. Signs of dog skin allergies include excessive scratching, licking and chewying.

Oksana Restenko/iStock / Getty Images Plus via Getty Images

Key Takeaways

Skin allergies in dogs are an immune response to triggers like fleas, food, or substances in the environment.
Most common signs include itching, redness, hair loss, and hot spots.
It's important to identify what type of skin allergy your dog has to treat the issue effectively.
Treatments may include medications, medicated shampoos, topical sprays, dietary changes like a special veterinary diet, or immunotherapy.
Early veterinary care helps prevent a bigger issue, like a serious infection or chronic skin damage.

Causes of Dog Skin Allergies

Skin allergies in dogs can appear in many different ways, some in specific locations of the body, or sometimes all over the skin. It’s important to work with your vet to determine the underlying cause of your pet’s skin allergies in order to develop the best treatment plan. The most common types of skin allergies in dogs are:

Atopic Dermatitis

Also known as environmental allergies, atopic dermatitis or atopy, this type of skin allergy is caused by an allergic reaction to triggers like plant pollen, dust mites, mold spores, or other environmental allergens. This may happen more during seasonal changes, known as seasonal allergies. The most common symptom is profound itchiness of the face, ears, paws, armpits, and abdomen. Medications, like Zenrelia, may be prescribed to control the itching and skin inflammation.

Contact Dermatitis

A contact dermatitis allergy occurs when your dog's skin comes into direct contact with irritants—like certain plants, chemicals, cleansers, caustic materials, or even things like dog shampoo—leading to localized itching and inflammation. Eliminating the allergen source will usually resolve skin allergy symptoms.

Flea Allergy Dermatitis (FAD)

Dogs with flea allergy dermatitis are hypersensitive to flea saliva, and even a single flea bite can trigger intense itching and skin irritation. Staying proactive on flea control preventive medication is critical to a dog’s health to not only prevent skin allergies, if they have FAD, but also to protect them from the diseases fleas can carry.

Food Allergies

While certain proteins like chicken, beef, and pork in your dog's diet can cause an allergic reaction, food allergies in dogs can be from other ingredients as well. Food allergies can result in skin problems, such as itching, redness, and a rash. In dogs, it can be difficult to determine the exact source of the food allergy, so your vet will likely recommend a veterinary diet with limited ingredients or made from hydrolyzed protein.

In the video below, veterinarians Jess Stroble, DVM, and Benjamin Carter, DVM, discuss the causes of allergies in dogs, as well the signs your dog has an allergy and how you can help.

Symptoms of Dog Skin Allergies

When dogs have skin allergies, pet parents may notice various symptoms, including:

Itching: Dogs with allergies often scratch, lick, or chew themselves excessively, especially in areas like the paws, armpits, belly, and rump. They may also rub up against furniture, carpet, or other surfaces to relieve itching and irritation.
Redness and inflammation: Allergic reactions can cause the skin to become red, inflamed, and visibly irritated.
Bumps: Raised bumps or hives may develop on the dog's skin, resembling mosquito bites. These can be small, red, itchy spots, scabs, or pimples that may be scattered across the body. Hives are often more consistent with acute allergic reactions than chronic skin allergies.
Hair loss: Excessive scratching and chewing can lead to hair loss or thinning of the coat in specific areas. Bald patches or uneven fur growth might also be noticeable.
Sores and hot spots: Dogs may develop sores or hot spots, which are inflamed and infected areas of the skin. These can be moist, red, and painful, often accompanied by oozing of serum (clear liquid), pus, or crusting. Hot spots typically develop as a secondary bacterial infection caused by excessive licking, chewing, or scratching that damages the skin’s protective barrier.
Itchy ears: Ear infections can cause your dog’s ears to be red and itchy. You may notice yellow, tan, or brown discharge in their ear canals. Crusting or scabbing around the ear tips can also be a sign of underlying skin allergies.
Restlessness: Dogs may appear restless or struggle to find a comfortable position due to the irritation, pain, and/or itching caused by the skin allergy and possible associated external parasite bites, such as fleas.
Irritability: Due to the discomfort and itching the dog may become irritable or exhibit signs of aggression, such as yelping or growling, when a sensitive area is touched.

Diagnosing Dog Skin Allergies

Veterinarians diagnose skin allergies by examining your dog’s skin and coat for signs of irritation and evaluating the pattern of itching. They often perform skin tests such as cytology or skin scrapings to rule out parasites and secondary infections.

Environmental allergies (atopic dermatitis) are diagnosed based on history, clinical signs, and ruling out other causes like fleas or food allergies.

Allergy testing does not diagnose atopy, but it can help identify specific allergens for immunotherapy treatment (more on that below). Intradermal skin testing, typically performed by a veterinary dermatologist, is considered the gold standard for allergen identification. Blood (serum IgE) testing may also be used, but hair and saliva tests are not considered reliable.

Dog Skin Allergies Treatment

Once a diagnosis is confirmed, a treatment plan may include:

Medications

Your vet may prescribe medications to treat itching, inflammation, and/or infections. Common medications to treat dog skin allergies include:

Zenrelia (ilunocitinib; JAK inhibitor) is an immune-modulating allergy medication for dogs that helps to break the itch-scratch cycle. It works well for both allergic dermatitis and atopic dermatitis in dogs over 12 months of age. The tablet is easy to give once a day, safe for dogs, and helps to reduce inflammation and improve skin allergy symptoms. Zenrelia can be given both short- or long-term to help with a dog’s skin allergies.

Apoquel (oclacitinib; JAK inhibitor) is another immune modulator used to help dogs over 12 months of age with skin allergies from atopy and FAD. Apoquel does not cure the skin allergies but is an effective treatment for itchy and inflamed skin. Apoquel comes as both a tablet and a chewable given either short- or long-term. Unfortunately, immunomodulators like Apoquel and Zenrelia do not help with skin disease from food allergies.

Cytopoint is a monoclonal antibody injection used to relieve itchy dogs that have atopic dermatitis. This injection is given by your vet every 4–8 weeks long-term for maximal effect.

Antibiotics and antifungal medications are used to treat skin infections. They can be oral medications, or topical applications like medicated shampoo and medicated mousse. These products help to remove excess bacteria and yeast on the skin that cause skin infections.

Steroids, such as prednisone, can be prescribed by your vet to help with inflammation and to help decrease the activity of the immune system caused by a skin allergy. Steroids can also be found in topical treatments like ointments and ear medication.

Antihistamines are not the most effective treatment for skin allergies in dogs, but they can be helpful for some cases of atopic dermatitis. Cetirizine (Zyrtec) and loratadine (Claritin) are antihistamines that might be recommended by your veterinarian for your dog’s skin allergies.

Medicated Shampoos

Medicated shampoos can help with many different symptoms of skin allergies in dogs. They contain ingredients to soothe, hydrate, and relieve itch.

Shampoos with antimicrobial action help with skin infections while those with steroids can help with inflammation and itch.

Medicated dog shampoos are a great adjunct therapy for most skin allergies, including contact dermatitis, as they remove the stimulus from the skin that is triggering the itch.

Topical Sprays

Topical sprays and mousse can help with skin infections from itchy allergies. An anti-itch spray can help reduce your dog’s itch sensation and urge to scratch, which in turn prevents further damage to the skin.

Flea and Tick Prevention

Flea and tick prevention is essential for all dogs but especially those that have skin allergies. Flea allergic dermatitis requires very strict flea control of all pets in the home and the environment to prevent skin disease from skin allergies.

Dietary Changes

If your vet suspects your dog has food allergies, then a novel protein, limited-ingredient hypoallergenic diet, or a hydrolyzed-protein diet will be recommended. A food trial takes at least 8–12 weeks, and be sure not to give any other treats, table scraps, chewable medications with meat proteins, or dog food during the trial, as these will interfere.

Immunotherapy

Immunotherapy uses both allergy shots or allergy oral drops that are specifically formulated for your dog’s allergies based on intradermal skin testing.

Intradermal skin testing uses tiny needles to inject environmental allergens into the dog’s skin in specific locations. These sites are then monitored over time to see if a skin reaction forms.

This form of allergy testing is done by a veterinary dermatologist.

Keeping Your Dog Itch-Free

To keep your dog itch-free, there are several preventive measures you can follow:

Regularly groom your dog. Bathing your dog and brushing their coat can help prevent matting and remove loose fur.
Provide your dog with a balanced and nutritious diet to support their overall immune system and skin health. Research suggests that omega-3 fatty acids (from fish oil) are beneficial to a dog’s skin and coat.
Use veterinarian-approved flea and tick prevention products like spot-on treatments, oral medications, and flea collars. Regularly check your dog for fleas and ticks, especially during peak seasons.
Regularly clean the environment, such as vacuuming carpets, washing bedding, and treating indoor and outdoor areas with pet-safe insecticides.
Manage your dog’s allergies, which may involve medications like Zenrelia, dietary changes, using hypoallergenic bedding, minimizing exposure to specific environmental triggers, or considering allergy shots (immunotherapy).

While these steps can significantly reduce flare-ups, many dogs with allergic dermatitis require long-term management with veterinary guidance.

Dog Skin Allergies FAQs

Can dog skin allergies go away on their own?

No. Allergies don’t usually resolve spontaneously, though seasonal signs may fluctuate. Secondary skin infections can occur if allergies are untreated, and your dog’s allergies may become more severe over time. If you suspect your pet is experiencing allergies, talk with your veterinarian.

Are certain dog breeds more predisposed to skin allergies?

Some dog breeds may be more prone to skin allergies, such as English Bulldogs, Boxers, and Labrador Retrievers, due to their genetics and skin characteristics. But any dog can develop allergies.

What is the most common skin allergy in dogs?

The most common type of skin allergy in dogs is atopic dermatitis (atopy) or environmental allergies, followed by flea allergy dermatitis and lastly food allergies.

Atopy may occur only during specific seasons (seasonal), persist year-round (nonseasonal), or be present year-round with worsening symptoms during certain seasons (nonseasonal with seasonal flares). Common environmental allergens in dogs include pollen from trees (oak, cedar, etc.), grass, and ragweed, plus dust mites, mold, and mildew.

When should I call my vet?

If your dog’s itching disrupts sleep, causes sores, or leads to hair loss, consult your veterinarian promptly. Early intervention prevents complications.

Can dog skin allergies be cured?

Dog skin allergies usually can’t be cured, but they can be very well managed. Most allergies are lifelong sensitivities, meaning your dog’s immune system will always react to certain triggers like pollen, fleas, or specific foods. The good news is that with the right treatment plan—such as medications, special diets, flea prevention, or allergy therapy—most dogs can stay comfortable and live happy, itch-free lives. Your veterinarian can help create a plan tailored to your dog’s specific needs.

DISCLAIMER

Indications For Zenrelia

Zenrelia is a prescription medication used to control itching and inflammation associated with skin allergies for dogs over 12 months of age.

Important Safety Information For Zenrelia

Read the package insert, including the Boxed Warning, before using this drug. For full prescribing information speak with your veterinarian, call 1 888 545 5973 or visit www.elancolabels.com/us/zenrelia.

WARNING: INADEQUATE IMMUNE RESPONSE TO VACCINES. Based on results of the vaccine response study, dogs receiving Zenrelia are at risk of an inadequate immune response to vaccines. Discontinue Zenrelia for at least 28 days to 3 months prior to vaccination and withhold Zenrelia for at least 28 days after vaccination. Dogs should be up to date on vaccinations prior to starting Zenrelia. Do not use in dogs less than 12 months old or dogs with a serious infection. Dogs should be monitored for infections because Zenrelia may increase the chances of developing an infection. Neoplastic conditions (benign and malignant) were observed during clinical studies. The most common side effects were vomiting, diarrhea and tiredness. Zenrelia has not been tested in dogs used for breeding, pregnant, or lactating dogs and has not been evaluated in combination with glucocorticoids, cyclosporine, or other immune suppressive drugs.