Canine Allergies and Atopy
The Grand Valley is turning green and maybe this has you reaching for the Zyrtec. Seems like many people experience allergy symptoms this time of year. The goal of my blog today is to help owners better understand and recognize pet allergies and how best to manage them.
Allergies can range from mild sneezing episodes to severe atopic dermatitis, a condition that has an underlying genetic component triggered by environmental allergens and food. Canine atopic dermatitis (CAD) is a complex, multi-factorial disease that is distressing for the affected dogs and owners. Dogs may suffer from intense itching causing them to self-traumatize their bodies with excessive licking and scratching. The resulting appearance can be alarming along with miserably uncomfortable chronic itching (pruritus) experienced by the dog.
Exposure to environmental allergens is primarily through the skin. Atopic dogs have abnormal lipid components in cells resulting in a defective epidermal barrier making them more vulnerable to allergens. Tests including skin cytology, skin scrapings, and skin biopsies are often needed for a diagnosis of exclusion in cases of atopy. It is important to understand that there is no definitive test for CAD diagnosis. Parasites affecting the skin such as mites and fleas can cause symptoms indistinguishable from CAD and should be ruled out and treated with preventive measures. Food allergies, which are different than environmental, can also trigger dermatitis flare-ups that mimic signs of CAD or can compound its symptoms. Bacteria and yeast are normal flora of the skin but with atopic animals, colonization and overgrowth happens more readily due to the factors mentioned. These secondary opportunistic organisms add to skin irritation and pruritus and must be addressed in order to manage CAD.
Recognizing and treating these symptoms early is helpful in managing the condition. Understanding the symptomatic therapy verses specific therapy is also helpful. Symptomatic therapy includes the use of medications to decrease itching such as antihistamines, antibody blockers (Cytopoint), cell inhibitors (Apoquel), essential fatty acids, shampoos/conditioners, and in some cases oral corticosteroids. It also includes management of secondary infections with antibiotics, antifungals, and topical therapies. These make up the bulk of treatments used by veterinary clinics. Specific therapies are also available for allergy and include avoiding the allergen if possible, like a specific food, and immunotherapy or allergy injections.
A systematic approach, proper follow up visits, and consistency are necessary for good management of these cases. With proper understanding and good communication, most cases respond well to therapy and patients can be managed to the relief of both owners and pets.