There are a number of substances that can cause allergies, or abnormal immune reactions, in dogs. The symptoms of such allergies can affect various parts of the body and may range from mild to severe. Some canine allergies are seasonal and some may occur year-round.
Types of Allergies
There are four basic types of allergies that dogs can experience. These may vary in symptoms and severity.
The most common allergy in dogs is caused by inhalation of particles in the air. Like humans, dogs may be allergic to tree or grass pollen, mold, mildew or dust mites. Some inhaled allergens are seasonal; other may be ever present in the home environment. Allergies to inhaled substances may result in respiratory symptoms, such as sneezing, coughing or wheezing, or in skin irritation. Airborne allergens may also cause itchy, red or watery eyes or nasal discharge.
Many animals, including dogs, can be allergic to fleas. It is not the bite, but the flea's saliva, that actually causes the allergic reaction. The itching that results at the site often causes the dog to chew itself. This behavior may result in bald patches, open sores or scabs on the skin that can all too easily become infected with bacteria. On dogs, the areas most commonly affected by fleas are the head and neck and the rump, just above the tail.
Surprisingly, a dog may develop an allergy to a food it has been eating for some time. Typically, it is a protein component in beef, chicken or pork that is the culprit. Food allergies can result in itching and scratching, but may also cause problems with digestion, such as vomiting or diarrhea. On some occasions, food allergies may cause disturbances in respiration.
Although the least common of canine allergies, contact with a particular substance or material can result in skin irritation and itching. Suspect materials may be found in collars, especially flea collars, and fabrics or bedding materials. Which material is creating the problem can usually be detected by careful observation of where on the dog's skin the reaction occurs.
Treatments for Canine Allergies
Antihistamines, such as Benadryl, given orally or applied topically, can provide relief from skin allergies of various types. Cortisone creams may also be helpful. In more severe cases, corticosteroids may be administered orally, topically or by injection. Because corticosteroids can cause serious side effects, they cannot usually be utilized long term. Bathing the dog may make the animal more comfortable by removing allergens on the skin while simultaneously relieving itching.
While desensitization using anitgen injections is possible with dogs as it is with people, this treatment only works about half the time and is very expensive. Where removing the allergen is an option, it is the simplest solution.