"Allergy Season" and Atopic Dermatitis
Allergy season has now arrived in Western New York, not only for we humans, but our canine and feline friends as well. As the pollen counts rise (primarily trees in the spring, grasses in the summer, and weeds in the autumn), our pets may begin to suffer. Manifested not by sneezing and runny itchy eyes as in people, but primarily by itchy skin, and ear and skin infections.
If your dog or cat has environmental allergies, you may have already visited Aurora Pet Hospital to have Dr. Meisner or Dr. Keem treat for an ear infection, or a pet that seems to be almost continuously scratching, both day and night. Pets with such allergies are said to be suffering from Atopic Dermatitis or simply Atopy.
Atopy results from allergies to things like molds, house dust mites, human dander (yes, your pet may be allergic to you!!), feathers, and pollens from trees, grasses, and weeds as mentioned above. Besides being itchy, atopic pets often have secondary bacterial infections of the skin known as a pyoderma, or yeast, known as Malassezia dermatitis. These organisms are not "caught" but are caused by overgrowth of normal inhabitants of dogs skin. Cats may also manifest such allergies by demonstrating symptoms of feline asthma, a respiratory disease that can cause wheezing, coughing, and difficulty breathing.
Our pets are usually first affected by atopy at 1 to 3 years of age, although this can vary in some. It almost always begins seasonally (spring to fall), but as time passes, it often develops into a year-round problem. The main clinical sign is itching, which quite often involves the ventral hairless areas of the body (armpits, groin, and between the toes), but may also involve the face, ears, and tail. The secondary bacterial and yeast infections often cause a distinct odor to develop. Other signs of atopy in dogs include conjunctivitis (itchy, red, runny eyes), chronic recurrent ear infections, along with salivary staining of the hair in chronically licked areas, darkening (hyperpigmentation) and thickening (lichenification) of the skin in areas affected chronically is also quite often observed.
Our ability to successfully diagnose and treat atopy in dogs and cats has increased dramatically over the past few decades. If we have ruled out things like flea allergy dermatitis, scabies, demodecosis, or primary skin infection, and strongly suspect allergy in a dog or a cat, Drs. Meisner or Keem can draw a blood sample screening test to determine if allergy may be the cause. If the screening test is positive, a more comprehensive blood test can be drawn, allowing us to determine the exact environmental allergens causing the atopy. Another method for determining causes of allergy is an intradermal skin test. This requires a veterinarian to inject small amounts of substances a pet may be allergic to (allergens) directly into the skin. After a fixed amount of time, the veterinarian can see which of these substances causes a reaction. Intradermal skin testing is best performed by a Board Certified Veterinary Dermatologist.
This may be a good place to mention that another common cause of allergy symptoms in dogs and cats is food allergy, or an adverse reaction to food as it is otherwise known. Unfortunately, blood and skin testing have been clearly demonstrated to be totally ineffective in diagnosing such allergies, and can therefore not be recommended.
Keeping a pet away from substances causing the allergy symptoms is the best means of control, but is very often impractical or impossible to do. Most dogs and cats can be successfully managed to minimize their symptoms, but unfortunately, cannot be cured. For many of these pets, the signs of seasonal allergy worsen with age. Treatment can be somewhat expensive and time consuming, is usually lifelong, and often causes a great deal of frustration for the owners of atopic pets.
Treatment for allergic disease must be customized to each individual case, just as it is in humans. It may first involve a food trial under the close direction of your veterinarian. We may also recommend medicated baths, especially if secondary yeast or bacterial infections are involved. Antibiotics and anti-yeast medications are often used early on, to make certain infection is not the primary cause of the itching.
Anti-inflammatory medications like corticosteroids have been traditionally used for temporary control of allergy symptoms, especially in cases of pets with a very short "allergy season". Antihistamines were often tried in the past, and may be useful in a small percentage of pets. Omega-3 fatty acids may be useful in reducing some inflammation, but caution is advised that many found over the counter in "fish oil" and other purported sources are virtually worthless. Atopica (cyclosporine) is an example of an older immunomodulating drug that has successfully been used in some patients in the past. It is quite expensive however, and there are newer drugs that are much more cost-effective to use, and with far fewer side-effects.
For pets who itch for many months and are severely affected, hyposenitization is often recommended. This involves administering the allergens causing the allergy by injection under the skin, or more recently under the tongue (sublingually) on a regular basis. This process may take up to a year to yield satisfactory results, but is often the least costly method of managing allergy in dogs and cats in the long run. Again, our doctors are always happy to discuss this method of therapy with our clients with atopic pets.
In January of 2014, an exciting newer class of drug to control allergy symptoms in dogs was introduced. The drug is called Apoquel, and is in a class of drugs known as Janus Kinase Inhibitors. Such drugs are also being used very successfully to treat rheumatoid arthritis in humans. This drug was found to be so effective in reducing allergy symptoms, and with few if any side-effects, that it quickly became almost impossible to obtain. While we at Aurora Pet Hospital have been able to continue to receive small amounts of this wonderful medication, supplies remain somewhat limited.
In closing, we want you to know our goal at this time of the year, is to keep your pet as comfortable as we possibly can, that being itch and infection free! Dr. Keem is a long-time member of the American Academy of Veterinary Dermatology, and has a special interest in diagnosing and treating diseases of the canine and feline skin. Each pet's allergy management needs to be individually tailored depending on their allergies, environment, and response to treatment. It is our hope that both you and your pet(s) are comfortable during this "allergy season" in Western New York.