Allergies are not restricted to the human animal, and our canines can be plagued with them as well. Some individuals are undeniably more prone to allergies than others, and it can be beneficial to know which factors may contribute to the type and severity of an allergic reaction or predispose your canine to developing the allergy in the first place. Dogs can be predisposed to any allergy and canines that are predisposed to reactions from one type of allergen are even more likely to develop further allergies.

Dogs can be affected by a number of different allergies. Although any dog can develop allergies, there are several factors that can predispose a particular animal to their development, such as genetic influence, environmental components, and immunologic factors.

There are multiple types of allergies, each with their own symptoms. They are generally categorized by type of allergen and the portions of the body they affect. 

Contact allergies - These are generally skin based reactions to allergens that can cause redness, itching, bumps, thickened skin, and hair loss. Your pet may scratch, lick, or chew areas affected by contact allergies. These may occur concurrently with other disorders, including other types of allergies. When they arise in the ears, they may lead to ear infections.

Dust and dander allergies - Dust and dander allergies show up as sneezing, stuffed up or running nose, and reddened itchy eyes. In serious cases, the respiratory system is also affected. Coughing, wheezing, and shortness of breath may become apparent. These allergens may also induce a contact allergy reaction. Dander is microscopic flakes of skin that can be found on animals with hair, fur, or feathers. This includes humans and other dogs. 

Food allergies - Food allergies generally surface within two hours from ingestion and usually result in hives or other uncomfortable skin rashes, chronic gas, obsessive licking, and vomiting. Anaphylactic shock caused by food allergies is a rarity among canines. 

Insect allergies - Allergies to proteins in the saliva or venom of insects can cause itching and swelling beyond the bite or sting site, hives, and vomiting. In severe reactions, you may also see swelling of the tongue and throat areas, breathing difficulties, or anaphylactic shock.

Pollen and mold allergies - Both molds and pollens can cause a stuffed or runny nose, irritated eyes, and sneezing, like in humans. Canines will also have contact allergy signs with pollen and mold sensitivity. The respiratory system may also become inflamed causing coughing and shortness of breath. These allergens are known to aggravate asthma or even induce it. 

Several breeds are prone to allergic reactions. Although some, like Maltese and Bulldog breeds, are better known for acquiring skin allergies, and others for inhalation or food allergies, such as Boxers or Cocker Spaniels, allergies of any sort are generally more prevalent for these breeds.

There are three main components to what can predispose your pet to allergies; genetic influence, environmental components, and immunologic deficiency or sensitization. 

Genetic influence - Certain breeds, such as Terrier and Retriever breeds, have a higher probability of developing certain allergies. Having one or more parent that has developed allergies increases the chances that your pet will also have an allergic reaction.

Environmental components - Environmental factors such as smoke, skin irritants, or even stress may increase the chance that an allergy will develop, especially during puppyhood. Certain allergens become more likely to cause a reaction with repeated exposures. The sap from many plants, such as tulips and hellebore, have this characteristic

Immunologic factors - Immunodeficiency disorders such as Omenn’s Syndrome and IPEX can increase the possibility that certain allergies will develop. Autoimmune diseases, in which the immune system is too active, also increases the probability of allergy development.

A predisposition to an allergy does not mean that the symptoms listed are always allergy related, and even dogs with no discernable predisposition can occasionally develop them. The best course of action is to get a definitive diagnosis from your veterinarian. There are many tests which can reveal if the symptoms are actually in response to an allergen, and possibly which allergen that is. The veterinarian is likely to request a complete blood count and a biochemistry profile which may expose eosinophils, a type of white blood cell that would indicate an allergic reaction.

Skin scrapings will often be taken from any affected areas for cutaneous cytology, which is the microscopic examination of the skin cells to look for issues like mites, yeast infections, or signs of disease. In some cases, a small amount of the suspected allergen or allergens may be injected into the skin to confirm that suspicion. In the event that the allergy is a food related allergy, dietary trials are often the best method to uncover which food the patient is reacting to.

If your pet already has predisposition factors for allergies, such as breed susceptibility or poor or unknown environmental circumstances when growing up, there are a few things you can do to reduce the probability of allergies developing. Take steps to reduce your pet’s exposure to common insect allergens such as fleas, ticks, and mosquitos. Monthly flea and tick medication is usually recommended for this purpose, as well as to avoid other flea and tick-borne diseases, and spray on insect repellents are also available for canines. These measures are most effective in the summer months when these insects are most active. 

Be aware of which plants are in your pet’s environment and avoid planting plants with known irritants within your dog’s reach. Reduce the allergens in the home by controlling dust and dander and vacuuming frequently. Some people who are prone to allergies prefer to use cleaning products that use milder natural ingredients rather than harsh chemicals. If your pet has frequent reactions to allergens, a switch to these gentler products may reduce the frequency of symptoms or prevent certain allergies from developing at all. If you are concerned about food allergies avoiding the most common allergy-causing foods, such as beef, chicken, dairy, wheat, and eggs, may prevent allergies. Choosing varieties that are specific about the type of protein in the food (i.e., duck or rabbit as opposed to meat and animal derivatives) may help determine which protein your animal is reacting to in the event that an allergy develops.

If your dog has developed an allergy, your veterinarian will give you specific instructions on how to treat it. Following the instructions that are given regarding oral and topical medication, including bathing requirements or dietary restrictions, should be followed faithfully and may need to be continued even after the symptoms are no longer apparent. Antihistamines are  usually the first medication given to combat allergic reactions if medication is required. However, antihistamines are only effective in approximately 20% - 30% of allergic canines and even those effects can fade with time, so steroids and corticosteroids may be required. If the allergy still isn’t under control your dog may benefit from allergy shots designed to desensitize the immune system. These are quite successful in the long run but can take six to nine months for the results to be noticeable.