Skin allergies in dogs: Vet's guide to signs and treatment

Skin allergies in dogs
(Image credit: Getty Images)

Is your pup incessantly itchy and scratchy? The presence of skin allergies in dogs is an uncommon but certainly uncomfortable condition that can occur at any age and in any breed.  

While it may be tempting to try home remedies or over the counter medications to treat your dog’s itching, these treatments rarely work and may even be harmful in some cases. Instead, it’s best to see your veterinarian to have the problem appropriately diagnosed and treated. From the selection of appropriate dog food for allergies to tackling environmental causes, read on to learn more about skin allergies in dogs and what you can do to help get your dog feeling better quickly. 

What causes skin allergies in dogs? 

Like humans, dogs can have allergies to foods, environmental allergens, or both. Both food and environmental allergies can result in cutaneous (skin) reactions.

Food allergies

A food allergy, better defined as an “adverse food reaction”, is an abnormal response to the ingestion of a particular food or food additive. The body incorrectly identifies the food molecules as an antigen, or a threat, and mounts an immune response against them, leading to symptoms like itchy skin or diarrhea.  

Food allergies most often develop after prolonged exposure to one type of food. In dogs, the most common food allergens are beef, chicken, lamb, and wheat. Allergies to soybean, milk, eggs, corn, walnuts, and possibly peanuts have also been reported. Dogs that have developed an allergy to one type of food may also develop allergies to additional foods in the future.

Environmental allergies

Environmental allergies results from a defect in the skin’s epidermal barrier, which is thought to be due to a combination of genetic and environmental factors.  These epidermal barrier defects allow allergens such as pollen to penetrate the skin surface and bind to immune cells, triggering an inappropriate immune response.

This results in an inflammatory process that leaves the dog itchy, red, and uncomfortable. Common allergens in dogs include pollens, grasses, dust mites, molds, and dander.

a dog scratching their coat

(Image credit: Getty Images)

Symptoms of skin allergies in dogs

Food and environmental allergies look very similar and are impossible to distinguish by symptoms alone. The common symptoms of allergies in dogs include: 

  • Chronic itching 
  • Recurrent skin or ear infections
  • Hair loss, redness, and crusting of the skin 
  • Self-trauma such as scabbing, hair loss, and saliva staining  
  • Frequent scratching or licking 

Other skin conditions can also cause similar symptoms, so if you suspect your dog may have allergies, it’s important to see your veterinarian first for a diagnosis and appropriate treatment. 

Your veterinarian will perform a full head to tail physical examination and may recommend some additional testing such as a skin scraping or sampling from your pet’s skin. Once the underlying cause of your pet’s itching and discomfort has been diagnosed, your vet will be able to develop an appropriate treatment plan to help get your pup feeling better.

Bloody wound caused by scratching on animal skin of short haired French Bulldog with severe allergies causing itching

(Image credit: Getty Images)

How are skin allergies in dogs treated? 

Treating food allergies

Food allergies are both diagnosed and treated using an elimination diet trial.  Your dog will be put on a special diet for a minimum of eight weeks. This diet may be a limited ingredient diet, a novel protein diet, or a prescription hydrolyzed diet.  Your dog must eat this food and no other food, treats, table scraps, or flavored medications for a minimum of eight weeks. 

If your dog’s skin symptoms resolve during the eight week trial, then this is diagnostic for food allergies. Your dog will need to stay on a special diet for life to avoid the ingredients that he or she is allergic to.  

Managing environmental allergies

Environmental allergies are more difficult to manage because your dog can’t avoid pollens or dust.  Environmental allergies are typically managed with prescription allergy medications. 

These may be given in the form of daily pills or monthly injections.  Some dogs with environmental allergies may also benefit from immunotherapy injections, where they are exposed to low levels of the allergens they are allergic to and thus slowly desensitized to them.  

Your dog first must have an allergy test to determine which environmental allergens he or she is sensitive to, and then your veterinarian can special order the injections for your dog.  

In both cases, your dog may also need to be treated for any skin or ear infections that have arisen secondary to the allergies.  Ear infections are typically treated with topical medications, such as medicated ear cleaners or topical ointments.  Skin infections typically require oral antibiotics to treat. 

Your dog may also need a course of steroids or prescription allergy medication to help reduce the itching and inflammation associated with these skin infections. Treating the underlying infection will help improve your dog’s itching and also make your dog’s allergies more responsive to treatment.

dog surrounded by dust

(Image credit: Getty Images)

Can skin allergies in dogs be prevented? 

Unfortunately, because allergies are caused by genetic and environmental factors, they cannot be prevented. We can only manage allergies as they occur.  We can prevent flare-ups of allergies by avoiding the offending allergens, such as by feeding a prescription diet to prevent food allergy flare-ups or minimizing dust in the home to reduce environmental allergies.  

And although allergies cannot be truly prevented, we do know that there is a genetic component to the development of allergies. This means it is best to avoid breeding dogs with allergies to avoid passing on this condition to the next generation of puppies.   


Allergies in dogs can cause a lot of itching and discomfort, but the good news is that they can be managed. If you suspect your dog has allergies, the first step is a visit to your veterinarian for appropriate diagnosis and treatment.  Remember to follow your veterinarian’s instructions closely to ensure the best outcome for your dog.  

Whether your dog has food allergies, environmental allergies, or a combination of the two, there are steps you can take to manage this condition and help get your dog back to feeling his or her best again.   

Elizabeth Racine, DVM

Dr. Elizabeth Racine is a small animal general practice vet covering all things pet health and wellness.  Her special interests include veterinary behavior, nutrition, and internal medicine.  As a freelance writer, Dr. Racine has written content for major companies in the industry such as the American Kennel Club, Merck Animal Health, Bayer PetBasics, Elanco, and CareCredit.  In her free time, Dr. Racine enjoys playing trampoline dodgeball, hiking with her beagle Dasher, and spending time with her three mischievous cats.