Dog allergies are often caused by the allergens found in pollen, animal dander, plants, and insects, but dogs can also be allergic to food and medication as well. These allergies can cause symptoms such as excessive itching, scratching, and grooming, rashes, sneezing, watery eyes, paw chewing, and skin inflammation.

When a dog’s body is exposed to one of the many allergens, the immune system can react abnormally. Spay/neuter is known to affect the immune system of dogs; creating a greater risk for negative reactions to vaccinations, a higher incidence of some cancers, and a greater incidence of dog allergies. Banfield (a nationwide chain of veterinary clinics) acknowledges that within its patient population, spayed or neutered dogs are 3 times as likely to present with atopic dermatitis (one of the most prevalent expressions of allergies).⁹²

Readers have advised us that their dogs suspected of having environmental allergies have often been put through a battery of allergy tests, often without any reliable results. The tests are expensive, and unless a specific allergen can be identified and removed, this process does nothing to help the ailing dog. When no allergen can be identified, often the treatment consists of various medications designed to suppress the immune system of the dog and hopefully ease their discomfort, (e.g. cyclosporine, Apoquel, corticosteroids, and antihistamines). These medications have serious side effects, as the links to each will outline. It is also important to note that if there is an infectious component (bacterial, viral or fungal) to your dog’s skin lesions, these immunosuppressive medications will interfere with your dog’s body’s ability to eliminate these infections. Additionally, these immunosuppressive medications adversely affect your dog’s ability to fight cancer.

Atopic dermatitis is much more common among spayed or neutered dogs, and can be a symptom of hormone imbalance in the dogs rather than an allergy. For conditions with an elevated risk associated with neutering, the gonadal steroids may serve a protective role. Diseases such as atopic dermatitis and IBD, where the mechanism of disease onset involves inflammation, higher concentrations of sex steroids present in intact dogs may exert an anti-inflammatory effect to prevent disease progression similar to what has been reported in mice.¹⁷³

In our case, Billy’s vet opted to do a skin biopsy to determine the cause of his dermatitis. The results of the skin biopsy indicated that Billy’s skin problem was due to an underlying endocrine disorder, not an allergy. We did not subject Billy to the trauma of allergen tests, and we did not administer dangerous immunosupressive medications either. This additional diagnostic step (skin biopsy) should be on your short list of testing requirements before embarking upon a series of skin allergy tests or administration of immunosuppressive medications.

Many of our readers have contacted us with concerns that their dog is experiencing alopecia (loss of fur or hair), in addition to the chronic skin infections, as Billy did. Apparently the explanations vets are currently providing for fur loss are much the same as we received years ago (e.g., allergies, skin infection, genetics, Cushings disease). If testing rules these items out, then the guardian is told the condition is merely cosmetic. Some of these same dogs also develop darkened skin in the areas of hair loss (as Billy did) , a condition termed by vets as “Alopecia X” (aka, Black Skin Disease, Adult Onset Growth Hormone Deficiency, Growth Hormone-Responsive Alopecia, Castration-Responsive Alopecia, and more recently, Adrenal Hyperplasia-Like Syndrome – termed in our time as atypical Cushings).

As evidenced by this article on the PetMD website, Alopecia X is generally described in veterinary practice as an uncommon, cosmetic skin condition with characteristic areas of hair loss (alopecia) and hyperpigmentation (dark or “black” skin).  As explained by Dr. Mark Macina, staff doctor of dermatology at NYC’s Animal Medical Center:

“This syndrome is recognized in both male and female dogs as an adrenal imbalance of the sex hormones (estrogen or testosterone), in combination with depleted production of melatonin…”

Sadly, we watched Billy develop most of the symptoms attributed to Alopecia X, including the loss of fur spreading across much of his body. We supplemented Billy with growth hormone and did not obtain any regrowth of fur. Billy was tested for Cushings. He did not have Cushings. It was assumed at that point in time Billy had what the vets term “atypical Cushings”. However, back then, as is the case today, the “cure” for atypical Cushings was the administration of drugs designed to destroy a part of the adrenal gland in the hopes that it would bring adrenal sex hormones back into balance. Our vet, to his credit, did not see the wisdom of destroying Billy’s adrenal glands (even if only partially) in the hopes of growing fur. However, upon his strong recommendation, Billy was supplemented with melatonin. This continued for a period of years. (At this point, I would refer you to our “Hormones and the Endocrine System” section of this website for a complete explanation of our experience with Billy’s loss of fur and blackened skin.)

The sex hormone imbalance characterized by atypical Cushings must be addressed by specific measures to inhibit those sex hormones in excess, and the supplementation of sex hormones which are deficient. Destruction of the adrenal gland in order to balance sex hormones, as recommended by the veterinary community at large, is ill-advised as it fails to remedy sex hormone deficiency and can cause great physical harm to the patient. Supplementation with melatonin is ineffective, and worse yet, a dangerous proposition. Failure to promptly and properly address Billy’s sex hormone imbalance, as well as years of misguided supplementation with melatonin, resulted in Billy developing type 2 diabetes. During the time period of 2006-2016, the incidence of type 2 diabetes in dogs has climbed 80%. Suffice it to say that the veterinary profession is so far off the mark with respect to their diagnosis and treatment of Alopecia X and/or atypical Cushings, this so-called “cosmetic” condition has become a serious life-threatening situation for our best friends.

We don’t want to leave this topic without addressing the subject of food allergies. Testing for food allergies is being reported to us more and more by our readership. We did go through a process with Billy which was designed to determine whether his alopecia and skin lesions were the result of an allergy to any food he was consuming. Billy was a poor eater, and we had him on a home-cooked diet for years. He also took several supplements, designed to make sure he was not deficient in any vitamins or minerals required for his optimal health. Billy had chronic diarrhea, and our vet prescribed a low daily dose of the antibiotic metronidazole which seemed to alleviate most of his GI tract symptoms. However, we were never comfortable with this ongoing use of antibiotics, in light of the fact that antibiotic resistance is recognized as a serious health issue which  must always be considered.

When a holistic vet advised us we should consider a food allergy as the underlying cause of Billy’s poor appetite and chronic diarrhea, we were eager to proceed. We were instructed to remove all grains from Billy’s diet. Also, we discontinued feeding Billy meats that had been through our normal food chain, e.g., chicken and beef. Billy was now given air-fried sweet potato french fries and a wild meat (duck, buffalo or venison) every evening. In the morning, Billy was allowed bananas with organic peanut butter. Billy did not improve immediately, as we had hoped. Over time, we sequentially removed the wild meats and went back to turkey, chicken, beef and lamb, and Billy’s condition did not change. It was concluded that Billy’s diet was not contributing to his aforementioned problems.

As a last resort, the holistic vet recommended supplementation with l-glutamine. Before administering l-glutamine to Billy, we did some research. L-glutamine is an amino acid that is utilized at a high rate by the cells compromising the immune system and the gut. The maintenance of plasma glutamine concentrations in patients at risk of immunosuppression (e.g. spayed and neutered dogs) has the added benefit of maintaining immune function. Animal studies have shown that inclusion of glutamine in the diet increases survival to a bacterial challenge.¹⁶⁸

In fact,  we found l-glutamine is considered to be a prime immunonutrient in immunonutrition therapy (altering immune system activity with specific nutrients) for critically ill patients, including those with serious burns. Experimental and clinical studies have demonstrated that l-glutamine, administered in animals or patients, can:

• abate intestinal injury
• accelerate repair of intestinal mucosa
• improve nitrogen balance
• abate immunosuppression
• maintain immune homeostasis
• ameliorate wound healing
• shorten hospital stay

Although the use of l-glutamine for supportive care of severely burned patients is now well established, the science of its use is still in its infancy.^168,169,170 

The holistic vet instructed us to discontinue the metronidazole and start Billy on L-glutamine powder (1 teaspoon mixed in his food; twice a day). The vet warned us his poop would be all colors of the rainbow for about a week, and then would improve. It happened just that way – yellow, orange and green poop, sometimes with heavy mucous. After one week, Billy’s diarrhea was gone and he was doing much better!

The vet did not advise us of any downside to the l-glutamine, and certainly Billy’s skin infections and digestion only improved with its use. A review of the literature does not reveal downsides with normal doses of l-glutamine; the only contraindication we have found to glutamine supplementation in moderation is that it does not appear safe for those suffering from epilepsy or prone to seizures. With respect to dosage, Billy weighed 60-65 pounds. Certainly a holistic vet should be able to help you with dosage if your dog is much smaller or larger than Billy.