Allergic Dermatitis in Dogs

Dog with Allergic Dermatitis

What Can Be Done? 

Allergies in people usually create respiratory symptoms; however dog allergies usually create skin rashes, smelly skin, ear infections, oily flakey skin, chewing, scratching and feet licking. In medical terms, an allergy is due to an immune mediated response to an antigen that makes its way into the body. 

The antigen can be ingested as a food, inhaled (pollen, molds, dust mites), migrate through skin, or injected into the skin by a biting insect. When an antigen makes its way into the dog’s body, the dog’s immune system recognizes the antigen as a foreign invader, and begins to attack it. 

While the immune system recognizes antigens and destroys potentially harmful invaders such as viruses, an allergy occurs when an otherwise harmless antigen also becomes an enemy of an overreacting immune system.

One of the most commonly developed allergies in dogs is to antigens injected into the skin by fleas:
• When a flea bites a dog with flea allergy dermatitis, immune cells in the dog’s skin overreact to the flea’s saliva.
• These cells surround the antigens and release enzymes in the skin.
• The resulting tissue inflammation causes irritation of the nerve endings in the skin and sends itching signals to the brain.
• Thickening of the skin due to inflammation compromises the skin’s normal barrier.
• The loss of barrier function allows easier entry of additional allergens through the skin, thereby multiplying the inflammation and itch cycle.

Commonly Used Treatments



Cortisone given by mouth or injection brings temporary relief by reducing the skin inflammation and suppressing the immune system. This is usually a quick means of providing itch relief. The downside is that cortisone not only fails to address the underlying allergy, but high doses or prolonged use of cortisone is also detrimental to the kidneys, liver, and other organs that are responsible for secreting natural hormones. Cortisone is a synthetic drug that mimics a hormone naturally produced by the adrenal glands called cortisol. High dose cortisone injections or tablets can negatively affect the production of natural cortisol by the adrenal glands, often leading to one of a multitude of metabolic disorders.


Other conventional medical treatments include giving antihistamines to help reduce the release of enzymes from the immune cells. Antihistamines have a reduced risk of complications when compared to cortisone administration; however they also are usually less effective in alleviating the symptoms.

Allergy Testing

Another treatment option is allergy testing by your veterinarian to create a list of substances, or antigens, that trigger a hyperactive immune system response. Once these offenders are identified, your dog can either be removed from exposure (works best for food allergies) or given small amounts of the antigens by injection. Gradually increasing the amount of the antigens injected on a strict schedule may slowly acclimatize the body to the antigen and reduce symptoms.

The Most Overlooked Step: Skin Nutrition

Many dog owners overlook the fact that supple, healthier skin is more resilient to problems. Because certain nutrients can help improve the skin’s resistance to dermatitis, it’s worthwhile looking into nutritional supplements that can strengthen connective tissue proteins.

Adding a nutritional supplement for healthy skin that contains omega fatty acids, phospholipids, minerals, amino acids, and vitamins to your dog’s diet can greatly diminish the effects of allergic skin disease. An excellent and inexpensive option is Breeder’s Formula® (formulated by veterinary nutritionists). This concentrated nutrient source supplies nutrients to help strengthen connective tissue proteins, especially collagen, thereby improving the skin’s resistance to dermatitis. 

In summary

Canine allergic dermatitis can be frustrating for you and your dog. With the help of your veterinarian, you can find the most effective measures to help your canine friend. Just make sure that your dog is receiving a healthy diet and consider including a concentrated nutrient source that promotes supple and healthy skin.

Scott Gravlee, DVM, CNS
Equine Nutrition Consultant
Life Data Labs, Inc