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Cornell Richard P. Riney Canine Health Center

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Atopic dermatitis (atopy)


Atopic dermatitis is a common skin disease characterized by excessive itchiness (pruritis), and it may affect as much as 10-15% of the dog population. 

It is caused by a reaction to substances in the environment known as allergens, and it’s a lifelong condition. While there is no cure, effective treatment can still help your dog maintain a high quality of life. 

What causes atopy dermatitis? 

A genetic component is suspected because certain breeds and families of dogs are predisposed to this condition.  

The skin of atopic dogs has a defective outer layer (epidermis). When allergens contact the skin, the immune system creates an inflammatory response, resulting in the signs of itchiness we see in affected dogs. Typical allergens include numerous types of pollens and molds, dust mites, dander (skin cells) and many other substances.  

What are the signs? 

The most common sign is excessive itchiness, and this can vary in intensity among dogs and can also change over time. The itchiness often has a seasonal component (40-75% of cases) which reflects the allergens involved, but it can progress to becoming a year-round condition.  

Dogs react by scratching behind their elbows, licking and chewing their feet, rubbing their faces and scooting. Initially, the skin will appear normal, but over time, there can be hair loss after scratching and licking. Areas of skin where the dog licks or scratches may appear red, and the hair in those spots may have a brown discoloration due to salivary staining.  

As the condition progresses, areas of the skin may become darker and thickened. Secondary infections can appear as rashes on the skin — often on the belly, behind the front legs and around the base of the tail.  

Which dogs are most commonly affected? 

Atopic dogs typically start to show signs between 6-months-old and 3-years-old.  

Many breeds of dogs are affected, including Labrador Retrievers, Golden Retrievers, Soft-coated Wheaton Terriers, West Highland White Terriers, Jack Russell Terriers, Bulldogs, Boston Terriers, Boxers, Pit Bulls, Shar Peis, Shih Tzus and Weimaraners, as well as mixed-breed dogs.  

It occurs more commonly in dogs where both parents are atopic, and it is seen equally in males and females.  

How is it diagnosed? 

There is no specific test for atopy, so a presumptive diagnosis is based on a number of criteria, including: 

  • Classic signs of itchiness 

  • Results of physical examination 

  • Successful response to atopic treatments  

  • Exclusion of other conditions that may have similar signs  

  • Fleas and other parasites, such as sarcoptic mange 

  • Bacterial and fungal infections of the skin and ears 

How are atopic dogs treated? 

Therapy is tailored to each individual dog’s situation and may change seasonally, as well as over time. Often, a number of different approaches are used at a time to improve success. The process may involve trying different options to determine what works best for each individual.  

Your dog will be examined for any signs of secondary infections on their skin and in their ears, and appropriate treatments will be recommended. 

Dogs with atopy may also have allergies to fleas and to certain foods. Your veterinarian will recommend that your dog be treated with an effective flea and tick preventive. If your dog is still showing signs of itchiness after treatments for fleas and atopy have been tried, then a food allergy may be considered.  

Topical therapies  

  • Can help remove allergens, moisturize the skin, and treat secondary bacterial and yeast infections 

  • These products include shampoos, rinses, mousses and medicated wipes.  

  • Some products also contain antihistamines and corticosteroids to help reduce inflammation.  

Allergen-specific immunotherapy (ASIT) 

  • Testing can be performed in order to identify what is causing your dog’s allergic reaction. This can be done by observing how your dog’s skin reacts to injections of small amounts of allergens, or by taking a blood sample and testing for IgE antibodies to a panel of allergens.  

  • In some cases, it might be possible to reduce your dog’s exposure to certain allergens, but often they cannot be avoided due their prevalence in the environment.  

  • Based on one of these tests, immunotherapy can be designed for your dog that is administered either by subcutaneous (under the skin) injection or under the tongue.  

Oral medications  

  • Can help reduce inflammation 

  • Corticosteroids (e.g. prednisone, prednisolone) are very effective and can be given in acute flare-ups. Because they are associated with side-effects, it is best to use the lowest effective dose for the shortest time possible, and then switch to other medications. 

  • Cyclosporine is effective in reducing itchiness and has fewer side effects than corticosteroids. 

  • Oclacitinib (Apoquel) is a newer medication that is very effective in providing relief to itchy dogs and also has fewer side effects than corticosteroids. 

  • Antihistamines (e.g. hydroxyzine, diphenhydramine, cetirizine) can be useful to prevent mild itchiness, but are less effective when excessive itchiness is already present.  

  • Essential fatty acid (EFA) supplements can be used in conjunction with other therapies. 

Injectable medications  

  • Lokivetmab (Cytopoint) is a monoclonal antibody that is given by subcutaneous injection usually every 4-8 weeks to reduce itching.  


Atopy can negatively impact a dog’s quality of life. It can also be frustrating, time-consuming, and costly for dog owners to manage. The good news is that most atopic dogs can be treated successfully by working closely with a veterinarian to prevent and manage flare-ups.   

More challenging cases may benefit from consultation with a veterinary dermatologist. Your veterinarian can help provide a referral if necessary or you can locate one through the American College of Veterinary Dermatology or the European College of Veterinary Dermatology.