The Itchy Dog

Atopic dermatitis and pyoderma, skin conditions seen commonly in dogs, are two of the most frequent reasons our pets will need to visit the veterinarian every year. Atopic dermatitis is an allergic skin disease that is caused by an immunological hypersensitivity to common environmental substances. Atopy is not very much unlike human “hay fever” with dogs reacting to similar things that their human owners do. Mold, grass, pollen, fungi and even house dust mites make people cough, wheeze and have a difficult time breathing. With dogs we typically see itchiness over parts or all of their body. They may incessantly chew, bite, lick, or rub their face, chest, armpit area and feet, causing irritation of their skin. Even the webbing between their toes can absorb allergens and make the whole body itch. The corners of your dog’s mouth, chin, groin,armpits and between the toes can become stained reddish brown from their saliva over time. They can lose fur from the excessive scratching as well. Your dog’s skin may become dry, greasy, or oily. Atopic dogs also commonly suffer from chronic ear infections as well.

Pyoderma, commonly referred to as “hot spots,” is a bacterial infection of the skin most often caused by an allergic reaction. Signs of pyoderma include red and inflamed skin, rash or lesions that may look like small bumps or raised round scabs. Pus filled blisters may also be present along with crusting, scaling, or loss of hair. Treatment includes antibiotics, steroids, anti-histamines, fatty acids, medicated shampoos, rinses and topical treatments. Usually, the hair around the lesions will be clipped by your veterinarian to enable deeper cleaning.

Whatever the underlying cause, allergies are difficult to address. Though allergies are rarely “cured,” early identification and intervention can keep them under control and at times can substantially diminish them. Totally eliminating exposure to environmental allergens isn’t possible because they are typically indoor/outdoor pets. Reducing indoor exposure can be helpful and cleanliness is key. Although blood tests are available, they aren’t always considered reliable diagnostic tools. Instead, intra-dermal skin testing is considered the “gold” standard to diagnose atopy. Suspect allergens are injected into the shaved skin area of the sedated dog being tested. In 5 to 15 minutes, positive reactions become swollen, red and elevated, while negative reactions fade away.

Hyposensitization, or immunotherapy, may be helpful to certain pets. The treatment involves a gradual process in which the dog’s resistance to allergens is increased by exposing it to gradually increasing amounts of the substance. Because improvement from immunotherapy is slow, injections are usually continued for at least a year. Maintenance injections may be needed for life.

Other kinds of dog allergies like food allergy, fleabite allergy, or contact allergy can cause itchy skin all year round. Food allergy occurs when the immune system begins to overreact to ingredients that the pet has eaten with no problems in the past. The list of known food allergens (substances that pets can be allergic to) is extensive and includes beef, poultry, dairy, eggs,lamb, pork, fish, corn, wheat, soybeans, preservatives, and dyes. Typically, it’s the protein source in a pet’s diet that elicits an allergic reaction.

A so-called “elimination diet” or a food trial is the only proven way to determine which food is affecting a pet. Elimination diets consist of feeding diets containing only ingredients that haven’t been offered to the pet in the past. These are called “novel” ingredients. The elimination diet can be thought of as a diagnostic test that may last up to 12 weeks. This test takes so long because the allergen may continue to stimulate your pet’s immune system for weeks after it is eliminated from the diet. The elimination diet will be the only food that a pet is allowed to eat during the trial period. During this time, no other food or treats may be fed unless they are restricted to the same “novel” ingredients in the elimination diet. Rawhide (usually made of cowhide), pig’s ears, and any other chew items or toys should also be avoided if they contain other ingredients. Even regular medications, such as heartworm preventives, must be given in a non-flavored form.

Remember that only after diagnosis is made can effective measures be started to control the skin problem. For good results, you will need to go to your veterinarian , most likely several times, in order to finally get a safe and effective treatment.