Jasper, a 2-year-old West Highland White, was looking more than a little off-color. In fact, he was in the pink, literally.




Beneath his snow-white hair, his skin was bright pink from his ears to his tail. The only other color represented on his body was a reddish-brown staining on the hair covering all four of his feet.




Jasper's owner claimed that Jasper spent most of his waking hours scratching at his ears and licking his feet, and that he had developed an unpleasant "musty" odor. It was fairly obvious that Jasper was suffering from allergies, one of the most common medical conditions we see in dogs and cats.




Allergies in dog and cats can be divided into three major groups:




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162; Flea allergy, or flea bite hypersensitivity, is the most common allergic skin disease in dogs and cats. Animals with flea allergy develop a reaction to molecules in the flea's saliva. Just one or two actively feeding fleas can cause signs of itchiness, hair loss, pustules and crusts in sensitive animals; often these lesions are concentrated on the back half of the body.




In temperate climates, there is usually a seasonal variation in severity, with signs increasing during the warmer months of the year (although fleas can survive indoors all year long and can continue to cause problems even in winter). Flea allergy is the easiest allergy to treat, as there are many effective flea control products on the market and the clinical signs can be controlled with low doses of steroids or antihistamines.




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162; The second most common allergy in dogs is atopy, in which the animal reacts to inhaled material, such as pollen, molds and dust mites. Common signs include itchiness, red skin, recurrent ear infections, feet licking and occasional red eyes and sneezing. Like flea allergy, atopy usually is seasonal in temperate climates, although indoor airborne allergens can be more of a problem in winter when pets spend most of their time inside.




Treatment for atopy can be challenging because it is difficult to limit a pet's exposure to allergens in the air. Traditionally, steroids and antihistamines are helpful in mild to moderate cases, and repetitive injections with extremely diluted antigens (identified as positive reactors in the patient by skin or blood testing) can be helpful in moderate to severe cases.




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162; The third major type of allergy is food allergy. Animals with food allergies most often react to the proteins or carbohydrates in their food. The signs are much the same as those associated with atopy (with occasional vomiting or diarrhea). However, there is little or no seasonal variation in severity. Food allergies also do not respond to steroids or antihistamines as well as flea allergy or atopy.




Complicating the diagnosis of allergic pets is the fact that many pets suffer simultaneously from two or even all three of these allergies. Veterinarians try to focus on the differences between the three.




Signs that are severe from spring through fall and then disappear in mid-winter suggest flea allergy or atopy, whereas itchiness that shows no decrease through the winter months is likely related to food. Response to a course of steroids can be another clue in figuring the type of allergy involved. With flea allergy and atopy, a course of steroids is like pouring water on a fire &

the signs respond quickly and may completely resolve. The same treatment in a food allergic animal may result in little or no improvement.




The traditional "gold standard" diagnostic for flea allergy and atopy is skin testing, in which small amounts of pure antigens, such as flea saliva, specific pollen or molds, are injected under the skin, then swelling around the injection site is measured and recorded.




A more recent method of testing blood for antibodies that react to specific allergens has become increasingly common, although the reliability of the results is controversial, particularly regarding food allergens.




The most common treatment plans try to address as many factors as possible. All allergic animals should have an effective flea product applied religiously &

this alone may reduce or eliminate clinical signs. Low-dose steroids or antihistamines are useful in treating flare-ups or as maintenance therapy in atopic or flea allergic animals. Allergy injections can be helpful in atopy cases that don't respond completely to the other medications.




The only effective treatment for food allergy is a diet that consists of a single protein source and a single carbohydrate course, also known as an elimination diet. The protein source should be one that the patient has never been exposed to in their previous diets, such as salmon, venison, rabbit or duck. The carbohydrate is often potato.




The diet can be prepared at home or there are several prescription diets available. The patient is put on an eight-week diet trial in which they receive only the diet and no other treats or food (not even flavored medication, such as heartworm preventative). If there is improvement after eight weeks, new elements can be introduced to the diet, one at a time, for a 10-day period. If there is any reaction during that period, the new element is considered a reactor and eliminated from the diet. The best time of year to conduct a diet trial is in the dead of winter, when there will be less interference from atopy or flea allergy.




Jasper received treatment for atopy and was put on a diet trial with salmon and potato prescription diet last winter. After eight weeks, he had improved significantly. On Jasper's annual exam this spring, his owner reported that Jasper hardly licked or scratched anymore, and I could plainly see that Jasper had returned to a lighter shade of pale that would do any West Highland White proud.




Dr. Tesluk practices at Ashland Veterinary Hospital.