Pet allergies most often show themselves on the skin. Allergic pets will often lick their paws, scratch their faces or show signs of skin irritation. Repeated scratching of itchy skin can cause hair loss and secondary bacterial infections.
Allergies are abnormal reactions to substances, including food ingredients, house dust or pollen. These substances, known as allergens, cause a reaction when an allergic animal makes contact with, consumes or inhales the allergen.
Flea Allergy
Flea allergy is one of the most common pet allergies. It is caused by a reaction to one of the 15 allergens found in flea saliva, and it can be activated by the bite of a single flea. Symptoms include intense itching, reddened skin and the appearance of papules (hard, red bumps). Areas of a pet's body most affected by flea allergy include the base of the tail, the spine, the inner thighs and the abdomen.
Surprisingly, many pets with flea allergy have few fleas on them when a diagnosis is made. In many cases, the pet tries to groom himself free of the offending fleas, which can cause an owner to discount fleas as a cause of the allergy.
Atopic Pet Allergies
Another common pet allergy is atopy. In this condition, an affected pet shows allergic symptoms on his skin, although the allergic reaction is caused by an inhaled substance. Atopy begins as a seasonal allergy, but it often progresses to a year-round condition as your pet ages. Atopic allergies often begin in pets that are between 1 and 3 years old.
Food Allergies
Another common pet allergy is a food allergy. These allergies also show skin symptoms, such as itching and redness, but they are caused by a reaction to an ingredient in your pet's diet. Although food allergies often seem to occur overnight, they actually result from the cumulative effect of an ingredient on your pet's body over months or even years.
How Pet Allergies Are Diagnosed
Depending on the cause of the allergy, your veterinarian will use a combination of tests to diagnose your pet's problem. These can include a complete physical examination with detailed history, blood tests or skin tests. Blood or skin tests use tiny amounts of known allergens to recreate an allergic reaction with a blood sample or under your pet's skin.
Food allergies are most often diagnosed with a 12-week exclusion diet that contains a source of both protein and carbohydrates that is new to your pet. If your pet's symptoms subside during the exclusion diet, a preliminary diagnosis of food allergy is made, and the diagnosis is tested by reintroducing ingredients from the former diet to create an allergic reaction.
How Pet Allergies Are Treated
In most pet allergy cases, avoiding the allergen trigger is the most important aspect of treatment. In the case of flea and atopic allergies, this means treating the pet and his home to remove fleas or allergens.
In the case of food allergy, a permanent dietary change is required to prevent future allergic reactions. Many owners opt to feed their pets the exclusion diet that helped diagnose the food allergy, while others pursue a home-cooked diet plan for their pets.