Friday, September 26, 2008

Allergies

Coastal Animal Hospital-Kitty Hawk

Well, it is once again that time of year. You know the signs-the constant jingling of your dogs collar as he incessantly scratches, the bald dog whose coat is so thin he looks embarrassed, the glowing dog whose skin is so red and hot you could roast a hot dog and of course the scabby dog who everyone avoids touching as though he has the plague. Yes, indeed it is allergy season.

There are 3 main types of allergies. 
The first and most common is the flea allergy, which left untreated leads to flea  allergy dermatitis. Second, would be atopic dermatitis or inhaled allergies, which tend to be a seasonal allergy which retrievers Labradors and Goldens are genetically predisposed. The least common allergy and probably most commonly misdiagnosed are food allergies which tend to be a year round allergy.

 All allergies, whether flea, inhaled or food, cause the immune system to become reactive which in manifested by the red and itchy skin. The allergic response weakens the skin's natural immunity. At this point the normal bacteria and fungi, which live on the skin then grow in numbers they would not normally and cause skin disease.

Typical signs of bacterial infections are pustules on the back or abdomen, which can be dry scabs or large, moist lesions, such as with "hot spots". Fungal infections can be seen on the skin and most commonly in the ears. It has a characteristic "sweet" odor when on the skin in large numbers and has a dry, scaly yellowish appearance and can cause the skin to become very thickened like that of an elephant.

It is important to remember that the skin infections, whether yeast or bacterial are secondary to the underlying primary allergy. These secondary infections must be treated with the proper ani fungal or antibiotic to resolve the infections, but unless the underlying allergy is identified and addressed the cycle will continue.

Flea Allergy - Flea saliva is very allergenic and can cause an intense itch response. Typically the scratching is focused primarily around the rump or tail area but generalized signs as skin redness, hair loss and scabs are the standard. These allergies tend to be worse in the spring, summer and fall seasons, but we see fleas year round in this moderate climate. It is important to treat not only the animal with the adulticide to kill the fleas, but also the environment so that flea egg and larvae can be eliminated or reduced so multiple phases of the flea life cycle are attacked, not just the adults on the animal. Your local veterinarian can answer all your questions about the different flea medications an developing a comprehensive flea treatment plan.

 Atopic Dermatitis - Inhaled allergies are very common on the Outer Banks. Unlike people who develop runny noses and itchy eyes, dog's primary allergic organ is their skin. Classic signs of inhaled allergies are foot and face itchiness as well as along the sides and underneath of the abdomen, although these symptoms can occur anywhere on the body. The allergens are usually environmental such as weed and grass pollen.

There are literally dozens of common inhaled allergens endemic to this part of the country from house mites to ragweed. Most inhaled allergies begin as seasonal allergies and have a tendency to worsen with age and for the most severely affected animals the symptoms may become year round in duration.

There are many different treatment approaches depending on the severity and duration of signs. Most dogs can be given short courses of corticosteroids or antihistamines to keep them comfortable during these high allergen periods. Other treatment options are desensitization injections or cyclosporine. We always advocate supplementation of omega 3 and 6 fatty acids to diet. This is an effective and natural way to help the dogs skin build up its immunity.

Food Allergies - Food allergies are different from the two before-mentioned allergies because this allergy is not seasonal but year round. Hallmarks of this allergy are chronic ear infections and feet chewing. Occasionally we also see chronic anal itchiness, yes the classic butt scoot.

The key to treatment is first identifying that this is the allergy, which is done with food trial. This is where the animal is fed a prescription hypoallergenic diet for a minimum of 4-6 weeks. During the trial period it is imperative that the dog be fed nothing but this diet, no milk bones, pig ears -even their monthly heartworm preventative must be non flavored. The most common cause of food allergies are corn, beef and dairy protein.

The hardest part about this allergy is that the owner must be very vigilant and disciplined, but once the allergy is established via the food trial, treatment is to continue the diet or begin reintroducing single proteins if you wish to identify the offending allergen. There are many other diseases which can mimic allergies, such as hormonal imbalances, skin parasites and cancer so be sure with your veterinarian if you have any questions about your pets skin health. 

We hope you all have a happy, safe and itch-free summer!
Stephen M. Samson DVM 
Coastal Animal Hospital
Kitty Hawk, NC

This article was published in Vol. 6 page 16 of Pampered Pet Guide.
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