Introduction

Anyone who has seen a dog constantly scratching or chewing on itself probably has seen a dog with allergies. Whether caused by inhalants in the air, flea or other insect bites or components of food, allergies can range from causing simple irritation to predisposing dogs to severe secondary infections. The precise cause of allergies in a given dog is difficult, but not impossible, to diagnose.

How Allergies in Dogs are Diagnosed

The most common cause of allergic reactions in dogs is also the most common cause of allergic reactions in people: seasonal hypersensitivity to something in the air or environment, such as pollen, a particular weed or something being harvested in the area. This usually can be diagnosed based on timing and environmental exposure. Flea bite allergies are also extremely common in dogs and are not particularly difficult to diagnose based on evidence of flea infestation. If the allergic reaction tends to last longer and occur randomly rather than seasonally, it probably is caused by something other than a seasonal environmental allergen. Advanced tests are available to identify specific allergens, and your veterinarian can discuss these with you in greater detail. Another, less invasive way to diagnose the cause of canine allergies is to remove possible allergens from the animal’s environment and then slowly reintroduce them, seeing when the problem subsides or recurs. Fabrics, household items made of rubber or plastic and even excessive dust can be allergy-inducing, so they should be considered in these cases.

If food allergies are suspected (and they are quite common in domestic dogs), your veterinarian probably will recommend an elimination diet. In a nutshell, this means putting the dog on a very bland diet with few ingredients (such as rice and maybe chicken), observing the dog’s signs if any of reacting to the food, and then gradually adding in other foods to assess how the dog reacts to them.

Obviously, it is important to determine the source of any allergic reaction in our dogs before a realistic treatment protocol can be established. Simply treating the affected area (for example, a skin lesion) may help relieve the symptoms temporarily, but the cause of the allergic reaction will remain and undoubtedly will cause more clinical signs in the future if the underlying allergen is not identified and removed or managed.