Dog Skin Allergies: Causes, Symptoms, and Treatment

If your dog is scratching themselves more often than normal and you notice red, inflamed or irritated skin, it’s time to investigate the source of the itching.  

Skin allergies in dogs could be the culprit. Skin allergies are the most common type of allergies in dogs. 

It's important to identify the cause of a dog's skin allergies with the help of a veterinarian. Once you know what's going on, your vet can start treatment immediately. 

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. The most common symptom is profound itchiness of the face, ears, paws, armpits, and abdomen.

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. 

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. 

• 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. 

• 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 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

Skin allergies in dogs typically require a trip to your veterinarian.  

Your vet will do a thorough examination of your dog, paying particular attention to their skin and hair coat. They will also take a sample of fur and material on the surface of the skin to examine under a microscope. 

Allergy testing can identify the specific allergens causing the reaction. While there are blood, hair, and saliva tests to determine allergies, dermal skin testing is the only reliable way to figure out a dog’s specific allergy. This type of skin testing often involves a veterinary dermatologist.   

Treatment of Dog Skin Allergies

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 great 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, 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 vacuum carpets, wash bedding, and treat indoor and outdoor areas with pet-safe insecticides. 

• Managing your dog’s allergies may involve medications like Zenrelia, dietary changes, using hypoallergenic bedding, minimizing exposure to specific environmental triggers, or considering allergy shots (immunotherapy).