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919-490-2000 H


Allergies in Dogs & Cats

Allergies in Dogs & Cats

    Symptoms from allergies are one of the most common reasons we see dogs and cats coming in for veterinary visits.  Typically owners will notice them itching, scratching, increased grooming behavior, and hair loss.  Some pets, especially dogs, will also have a strong smell to the skin.  The odor is caused by infections with yeast or bacteria that develop secondary to damage to the skin barrier.  While these infections usually respond to treatment with antibiotics and antifungal drugs, if the underlying allergy is not addressed they will keep coming back, which can be very frustrating for owners.   Our veterinarians can work with your pet to identify the underlying cause of your pet’s allergy, and help with management strategies to keep their symptoms from coming back. 

cat dog

    The three big categories of allergies in our dogs and cats are; allergies to insects - especially fleas, allergies to certain foods, and allergies from environmental causes like pollen, grass, or dust mites.  Any of these allergens result in the symptoms of itching and hair loss but often the pattern of affected areas on the body looks different. 

Flea Allergy Dermatitis

    Just like people are allergic to mosquito saliva which causes an itch when they bite us, our pets are allergic to the saliva of fleas.  While all pets experience some discomfort from flea bites, in those that are highly allergic it may only take one or two fleas to set off extreme itching.  You may not always see the fleas, especially in cats since they are such efficient groomers and will swallow them like we would swat at a mosquito.  As veterinarians, we have a stronger suspicion of flea allergy if the back half of the body is more severely affected than the front, especially around the lower back, the tail, and the thighs.  The good news is that there are multiple safe and effective products to manage fleas in our pets.  Newer flea/tick medications that have systemic effects such as Nexgard, Bravecto, and Revolution are often recommended in pets with extra sensitivity as they have faster flea kill times than most of the older topical medications available.  It is very important to treat all the pets in the household year round in North Carolina to prevent re-infestations. 

Food Allergies

 In people we often think of severe (anaphylactic) allergies to foods like peanuts or shellfish, but in our pets food allergies are one of the possible causes of skin lesions and itching.  The pattern of lesions on the body with food allergies can be similar to environmental causes including the ears, armpits, and belly, but will commonly also include thickened red skin around the anus and underside of the tail.  Other symptoms may include frequent bowel movements, soft stools, vomiting, and excessive gas.  The most common food allergens identified in dogs are beef & chicken, and in cats the most common are allergies to beef or fish.  The best way to identify food allergies in pets is through a hypoallergenic diet trial lasting 8-12 weeks, if symptoms resolve you can then offer key ingredients of the old diet individually to see what your pet reacts to.  There are two approaches to hypoallergenic diets, hydrolyzed diets or novel protein diets.  Hydrolyzed diets are typically chicken based but the proteins have been broken down into very small pieces to decrease the chance of them causing an allergic response.  A novel ingredient diet has ingredients your pet has never eaten such as salmon & sweet potato or rabbit & pea.  It is best to purchase a prescription diet specifically formulated for pets with allergies during the trial period since many pet foods available over the counter can have traces of other proteins from being made using the same processing equipment.  It is also very important that table-scraps, flavored medications, or eating another pets food, are all avoided during the trial period. 

Environmental Allergies (Atopy)

   Environmental allergies, also called Atopy or Atopic Dermatitis, is a common condition in both dogs and cats.  Allergens such as pollen, grasses, dust mites, and weeds that may cause hay fever in people, can be both inhaled and absorbed through the skin barrier to cause itching in animals.  Dogs usually have a pattern of affected areas including around the eyes, ears, muzzle, feet, armpits, and groin.  Cats often have itching and hair loss around the face and ears, the lower belly and limbs.  Usually symptoms begin between 1-3 years of age and may be more severe in certain seasons, especially spring and fall.  Specific allergen testing can be performed by either a blood panel measuring a response to trees, weeds, grasses & other allergens by region, or the “scratch –test” where very small amounts of allergens are injected under the skin and the reaction is compared to histamine.  The results of testing can be used to tailor allergy vaccinations for your pet (immunotherapy) that are given at home on a regular schedule to desensitize the immune system and prevent the allergy response.  Aside from immunotherapy, several medications are available to help alleviate allergy symptoms including anti-histamines, Atopica, Apoquel, and corticosteroids.  Medicated shampoos and ear cleaning products are also often prescribed to treat and prevent the secondary infections caused by allergies. Your veterinarian will work with you to determine the best approach to manage allergy symptoms in your pet. 

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