Facts About Allergies in Dogs

Allergies in dogs can occur after the age of 2, and they are due to different factors such as chemicals, pollens, dust mites, parasites or food. There are some facts about allergies that shouldn't be ignored. These can help you understand the dog's condition and control the allergies.

Allergies Are a Problem of the Immune System

Canine allergies occur when the dog is in contact with an irritant and the immune system doesn't tolerate that irritant, releasing histamines. Histamines are substances that will trigger the symptoms of the allergies. Dogs that have a healthy immune system won't develop allergies. Dogs that have a weak immune system are prone to allergic reactions and they can develop allergies to one or more factors.


Typically, the allergens are airborne and are either inhaled or enter the dog's skin pores. Food allergens will enter the dog's system through digestion. Once the immune system identifies these irritants, it will react immediately and cause the allergy symptoms.

Types of Allergies

The allergies can be of several types, depending on the allergen:

  • Inhalant allergies or atopy (to pollens, chemicals, smoke)
  • Food allergy
  • Contact allergy

Symptoms Can Differ in Intensity

Not all dogs display all symptoms of allergies, and the symptoms may differ in intensity. Some dogs may only sneeze and have minor rashes, while others may experience itchiness and cough and have respiratory issues. The severity of the symptoms will depend on the response of the immune system of each dog in part.

Detection of Allergies

Depending on the type of allergies suspected, there are tests that can be performed. Inhalant allergies are easy to detect through either blood tests or skin tests. Food allergies can only be detected through food trials, which can take several months. Contact allergies can be identified through trials, by removing one possible allergen at a time and observing whether the dog's condition improves.

Severe Allergies Can Be Fatal

Severe allergies or anaphylactic shock may happen in rare cases and will manifest through the severe swelling of the face and limbs, and the constriction of the airways. If treatment is not administered immediately, this type of shock can be fatal. An epinephrine shot will reduce the swelling and will allow the dog to breathe normally, but the allergen should be identified and avoided in the future.

Dogs Respond Differently to Allergy Medication

There is no medication that will work equally well in all dogs with allergies. The vet may experiment with different types of treatment to find the best one to control the allergies.

Complete Allergy Healing Is Rare

Allergies in dogs can be managed, but will typically not be cured. Allergy shots may alleviate the symptoms and in rare cases, the dog can heal and be allergy free. However, antihistamines and steroids won't cure allergies; they will only reduce the symptoms. If the dog is not exposed to the allergen, he won't have allergy symptoms, but he may develop allergies to other factors.