The short version
Like people, dogs can be allergic to various substances, including plant particles and other substances in the air or substances in food. These substances are called allergens. Allergens are substances that, when inhaled or absorbed through the skin, respiratory tract, or gastrointestinal tract, stimulate the immune system and the release of histamine and other substances. This results in inflammation, signs of which include reddening of the skin (erythema), swelling (edema), and itching (pruritis).
Airborne Allergies (Atopy or Canine Atopic Dermatitis)
The diagnosis of airborne allergies is difficult because there are no tests available that can positively identify the condition. Instead, diagnosis is based on age, breed, signs, and disease history (such as age when the signs first started and response to treatment). Other causes of signs must be excluded. Allergy testing cannot diagnose allergies, but it can be used to identify the offending allergens and to formulate a specific immunotherapy treatment program.
Atopic dermatitis is a lifelong disease that requires longterm management and regular veterinary examinations. Treatment involves a number of options: avoidance of the offending allergen(s), controlling the signs of itching, bathing and improving coat hygiene, controlling flare factors (such as fleas or secondary infections), and immunotherapy (for example, an allergy vaccine). A good management plan requires the use of several different treatments, the understanding and reasonable expectations for response from the pet owner, and frequent progress evaluations so that the plan can be adjusted as needed. Treatments used for sudden flare-ups often vary from those used for longterm management. Follow your veterinarian's instructions closely.
Treatment takes a longterm commitment. You must be willing to follow instructions accurately, be patient, and be able to communicate effectively with your veterinarian. Treatment may initially increase signs. If this occurs, contact your veterinarian immediately. Improvement may not be visible for 6 months, and a year of treatment may be required before you can tell if the immunotherapy is working. The best way to evaluate the treatment is to compare the degree of disease or discomfort between similar seasons. Anti-itch medication and antibiotics are often required during the initial phase of treatment and may be necessary intermittently throughout the year. Do not assume that immunotherapy has failed if signs appear during therapy because they may be due to another cause (such as an infection). Talk to your veterinarian if signs return, change, or do not resolve during treatment.
Food Allergies
Among pets, food allergies are less common than airborne allergies. Any breed can develop food allergies, but there may be an increased risk for Labrador Retrievers, West Highland White Terriers, and Cocker Spaniels. Signs of food allergy are similar to airborne allergies except there is little variation in the intensity of itching from one season to another. The age of onset is variable. The distribution and intensity of itching varies between animals.
The trial diet should be fed for up to 3 months. If marked or complete resolution in signs occurs during the elimination diet trial, food allergy can be suspected. To confirm that a food allergy exists and improvement was not just coincidental, the dog must be given the previously fed food ingredients and a relapse of signs must occur. The return of signs is usually between 1 hour and 14 days. Once a food allergy is confirmed, the elimination diet should be continued until signs disappear, which usually takes less than 14 days. At this point, previously fed individual ingredients should be added to the elimination diet for a period of up to 14 days. If signs reappear, the individual ingredient is considered a cause of the food allergy.
The foods dogs are most often allergic to include beef, chicken, eggs, corn, wheat, soy, and milk. Once the offending allergens are identified, control of the food allergy is by strict avoidance. If your dog is allergic to other things (such as plant pollen or fleas), identifying underlying food allergies will be harder. Infrequently, a dog will react to new food allergens as it ages.
For More Information
Also see professional content regarding food allergies or atopy.
Frequently asked questions
Allergies dogs?
The Merck Veterinary Manual covers this in the article linked on this page. Like people, dogs can be allergic to various substances, including plant particles and other substances in the air or substances in food. These subst… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.
Allergies dog eyes?
The Merck Veterinary Manual covers this in the article linked on this page. Like people, dogs can be allergic to various substances, including plant particles and other substances in the air or substances in food. These subst… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.
Allergies dog paws?
The Merck Veterinary Manual covers this in the article linked on this page. Like people, dogs can be allergic to various substances, including plant particles and other substances in the air or substances in food. These subst… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.