Counter Surfers Unlimited

  Home                      Stories & Such   
 

Labsr4U Pawsitive Advice

Allergies

The following article was written by Rachel Peeples, DVM  

The term allergies is a general term for a variety of conditions in which the immune system "overreacts" to foreign material that is not harmful to the body. The immune system's job is to protect the animal from harmful material be it toxins, bacteria, viruses, etc. It does this by recognizing foreign substances, or antigens, and producing protective proteins, or antibodies, to them. The antibodies bind to the antigens and stimulate the body's immune cells to destroy the antigen.

During this process, chemicals are released that make the blood vessels in the area of the antigen become leaky producing swelling, that increase blood flow to the area producing heat and redness, that initiate itchy and pain sensations, and that sometime cause systemic signs like fever and shortness of breath. Normally, these are all defense mechanisms that serve to remove the dangerous foreign material from the body and keep the animal healthy.

Sometimes, however, the immune system reacts to substances that are foreign but are not harmful. These substances are called allergens. Animals can be allergic to absolutely anything just as people can. And what they are allergic to and how allergic they are is highly individual. There is some evidence that allergies are partially the result of minor abnormalities in the immune system that are genetically linked. So, breeding a strongly allergic dog or bitch is not recommended.

The most common allergies in dogs are flea allergies, atopy (or inhalant allergies), and food allergies. Less common are contact allergies.

Flea allergy is just what its name implies -- an allergy to fleas. The classic presentation of a flea allergy is a VERY, VERY itchy dog that has hair loss in a V-shape along the back at the base of the tail, along the stomach, and along the back of the back legs. These areas of hair loss also have reddened skin that can become darker (hyperpigmented) and thickened (lichenification). Often scratches and other lesions occur as a result of the scratching and biting to relieve the itchiness, and secondary bacterial infections are quite common. Diagnosis is based on the presence of fleas (it takes only one in very allergic dogs), the distribution of the lesions, and rarely on actual skin allergy tests. The treatment that is most effective is keeping the dog and its environment flea free. That is much easier today than in previous times due to the monthly flea products like Advantage and Top-Spot. As word of caution -- Program is an excellent flea control product BUT is requires that the flea bite the dog to be affected. Program alone is not going to work for the flea allergic dog. Program in combination with adult flea control products is a very powerful and effective combination.

Atopy is another common allergic condition. It is an allergic reaction to inhalant allergens like pollen, dust, dried up insect parts, animal dander (yes your dog can be allergic to your cat :-)!!), molds, etc. The common presentation of atopy is an itchy dog that constantly scratches or licks its feet, face, and ears. Often these dogs will drag their muzzles across the carpet. Dogs with atopy often have a history of recurrent ear infections and skin infections. Mild atopy can present as merely mild itching and slightly reddened skin. Severe atopy can present as intense itchiness, hair loss especially on the face and feet, red staining on the feet from licking, hyperpigmented and lichenified skin, and often secondary bacterial infections from the trauma of scratching. Typically, atopy is seasonal, that is, it is worse in the spring or fall. But sometimes atopy can be year-round especially for allergies to house dust and animal dander. Diagnosis is based on the signs, the history of being seasonal and VERY responsive to antihistamines (benadryl) and steroids (prednisone), and a positive allergy skin test for airborne allergens. Treatment consists ideally of allergy "shots" to desensitize the animal, antihistamines, regular baths, and only occasionally steroids. Average age of onset is one to two years and the condition tends to worsen as the animal ages if untreated.

Food allergies are one of the more frustrating allergies to deal with for it is often a diagnosis of exclusion. That is, it is diagnosed after flea allergies and atopy have been ruled out. Food allergies occur when the immune system reacts to a substance (usually a protein) in the diet. Signs can mimic any of the allergies -- with hair loss, red skin, thick skin, etc anywhere. Often the feet and ears are the two areas most affected but that is highly variable. The dog is itchy though not as much as with flea allergies or atopy, and the itchiness responds poorly to antihistamine or steroid treatment. Often food allergic dogs have a history of year-round itchiness and recurrent ear infections. Diagnosis is often made by ruling out flea allergies and atopy in itchy dogs. Food trials are the definitive means of diagnosing food allergies. In a food trial the dog is fed a hypoallergenic diet that has one protein and one carbohydrate source. Common hypoallergenic diets are rabbit and potato, fish and rice, venison and potato, and more recently kangaroo and potato. Let me take a moment to comment here about lamb and rice diets. Initially, in the United States lamb and rice was the hypoallergenic diet simply because there was very little lamb dog foods available at the time. For some reason, the dog world has gotten the idea that lamb and rice is a better diet than the others for all dogs. This is simply not true especially since most lamb and rice diets today are lamb and rice and a bunch of other stuff (read your labels). So, do not assume that just because you feed a lamb and rice diet that the diet is hypoallergenic or will prevent food allergies from developing. Anyway, once the hypoallergenic diet is chosen and feeding initiated, owners must be very dedicated to not feeding anything BUT the diet. It takes approximately 6-10 weeks for improvement to be seen. If improvement does occur, then the dog can be fed its original diet to see if its allergic condition returns to absolutely confirm that the food is the source of the allergen. Then the dog is returned to the hypoallergenic diet and kept on it for the rest of its life. Often, this is the only treatment that is needed for food allergic dogs. Antihistamines and steroids are typically ineffective in food allergy dogs. Typical age of onset is less than 6 months and then greater than 6 years. Rarely are vomiting, diarrhea, or other gastrointestinal upsets associated with food allergy.

Frustratingly, allergies are often a combination of these three types especially food allergies and atopy. Diagnosing and treating these combinations is difficult at best and impossible at times. Steroids have long been the mainstay of allergy treatments, but as the veterinarian community recognizes more and more the damage that long term steriods do the more it tries to incorporate a multifactorial approach to treating allergies so that the amount of steroids can be reduced to as low as dose as possible if not eliminated altogether.


          Diet -- even in atopic and flea allergic dogs diet can help reduce signs. Diets high in Omega-3-fatty acids (like Eukanuba) can help reduce allergic reactions. Homemade diets are becoming more and more popular for allergic dogs and many dogs respond dramatically to a preservative free, freshly made diet. The drawback to this is the time that it takes to research how to properly make a homemade diet and the time to actually make it.

          Omega-3-fatty acids -- these fatty acids replace Omega-6 fatty acids in the body and thereby lead to less chemicals produced that initiate allergic signs. In fact, some of the chemicals Omega-3 fatty acids are converted to reduce allergic signs. Fish oil and flaxseed oil are two good sources of Omega-3 fatty acids.

          Vitamin E, C, and A -- these are considered anti-oxidants and work by reducing the effects that body chemicals have in producing allergic signs. Acupuncture -- stimulation of certain acupuncture points will help reduce the "overeaction" of the immune system Antihistamines -- while they do produce drowsiness in animals they are less harmful in the long run than steroids. They work by inhibiting histamine which is one of the main body chemicals in producing allergic signs.

          Topical shampoos and conditioners -- these help soothe the skin and treat it from the outside in. Oatmeal baths have long been known to reduce itchiness. Some of the topical treatments contain antihistamines and other drugs that help reduce redness and itchiness.

          Herbs -- each dog needs to have an individual protocol formulated but some herbs that help with allergies are Scutellaria, Tribulus, and Capillaris.


Allergies can be very frustrating for the dog, the owner, and the veterinarian to deal effectively with. Some dogs respond so well to treatment that all signs resolve, others are brought to a manageable level, and, unfortunately, others are never made comfortable. Since there is some evidence that allergies in part are hereditary, breeders should strongly consider not breeding allergic dogs (and bitches) especially the ones that are severely allergic.

Back to Pawsitive Advice