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Dog Allergies – From Causation to Treatment


Dog allergies happen when the immune system overreacts to something it perceives as a threat, when it is not. Itching skin from something as benign as laundry detergent, sneezing due to pollen in the air. There are two terms used to refer to the materials that cause a reaction, antigen and allergen. Antigen covers any thing that causes a reaction whereas allergen covers just air borne or ingested causes.

You can put antigens into three categories, what your dog eats (dyes, the actual food, additives, mites, preservatives), what your dog touches (fleas, certain soaps, materials, dust mites) and finally what your dog breathes (pollen, dander, preservatives from the deck, cigarette smoke, perfume, carpet underlay particles). It is quite possible for a dog to have allergies from more than one category and allergies are additive meaning the more they are exposed, the worse the symptoms become.

Common Dog Allergies


Flea bites are the most common cause of dog allergies and they can lead to loss of hair, irritated skin and constant scratching that causes skin wounds. It is actually the flea saliva that their immune system is overreacting to. Other common dog allergies include beef, wheat, eggs, rice, dairy, pollen, chicken, corn, fish, yeast, pork, soybeans, rice and lamb.

Causes of Dog Allergies

As mentioned it is your dog's immune system overreacting to something. Normally the immune system protects against foreign bodies and reacts strongly against things like bad bacteria but it does not react to harmless materials like wheat or any of things mentioned already. In a dog with allergies when the immune system's white blood cells detect an allergen they release histamine. This leads to the capillaries dilating allowing blood vessels to leak fluid causing the area to be itchy, swollen and hot. Treatments involve blocking the histamine or the white blood cells.

What Breeds are More Affected?

Scottish Terriers

Labrador Retrievers

English Setters

Boston Terriers


Golden Retrievers

Irish Setters

Cocker Spaniels


Cairn Terriers



Fox Terriers

Miniature Schnauzers

Wheaton Terriers


Shar Peis

Sealyham Terriers


Lhasa Apso

West Highland White Terriers

Senior dogs are the least affected because their white blood cells are not as efficient at releasing histamine. As a dog ages and enters its senior years its symptoms well lessen.

Symptoms to Look For

The most common symptom is itching causing the dog to scratch. The most usual areas affected are the ears, feet, groin, eyes, anus, and arm pits. The dog may shake his head, bottom scoot, bite or scratch their belly and rub their face. The scratching can cause skin damage and yeast can grow leading to complications like Malassezia dermatitis which also has a bad odor or ear infections that lead to bad bacteria multiplying. Other symptoms include vomiting, gas and diarrhea.

How Do You Know if Your Dog has Allergies?

There are tests that can be done in a lab. Some are blood tests and there are also skin tests. RAST will check for reactions from your dog to things like pollens, fleas and food mites. However sometimes the results are not easy to read. Another skin test that could be done is the intradermal skin test. They take small amounts of possible antigens and inject them into a small area of the skin. But again results are not easy to interpret.

Dogs and Food Allergies

If you suspect a food allergy you can have him undergo food allergy elimination trials. Your dog can be put on a special diet like Hill's Z/D diet where nothing will trigger the dog's immune system. After so many weeks you can start to introduce other foods like kibble. After so long on kibble if there is no reaction you can then add another food. Slowly you can find the foods that trigger the allergic reaction. It is important to not give any other foods though, no treats, bones, chews and so on.

Another way to go about it is to do food that is home cooked for your dog. He eats a protein and a carbohydrate that he has not ever eaten before for example lamb and carrots, or deer and peas. For several weeks that is his only source of food. Then you can start to slowly introduce other foods one at a time.

What can You Do to Help a Dog with Allergies?

If you know what triggers them you can try to avoid them. Don't take your dog for a walk when the grass is freshly cut for example. You can also keep your windows closed, use an air filter, use a HEPA filtered vacuum cleaner and dust with a damp cloth. Be sure to use perfume free detergent and avoid smoking. Cover the bedding in cotton, try to avoid harsh chemical cleaners and strong perfumes or scents. Also keep dogs with allergies away from areas like damp basements, laundry rooms, garages and dusty areas.

When he goes outside onto the grass and then comes back in clean his feet. When pollen counts are higher in the morning and evening keep him indoors. Avoid using cedar chips and cedar dog houses. Make sure the food is stored so that it does not get dusty and instead of plastic food bowls use glass or stainless steel.

Treatments for Dog Allergies


There are natural and medicated options. Yucca is one natural option as it is anti-inflammatory helping with the symptoms of allergies. It should be given daily either in food or topically on the itching area. Another way to help prevent your dog's immune system from overreacting is to incorporate more omega 3 fatty acids into his diet. There are chews or a liquid that can be mixed with his food. However only about 1/8 of dogs are helped.

For medicated treatments you could try some over the counter options like medicated shampoos and conditioners. Examples include Relief Shampoo, Allermyl shampoo and HyLyt Essential Fatty Acid shampoo.