Itch, Itch – Scratch, Scratch: The Truth Behind Your Pet’s Allergies

Most pet owners experience it at one point or another. You hear a distinct “cling, clang, cling” coming in the direction of your dog as he or she scratches their ear and rattles their dog tags incessantly. We all know that unmistakable sound of your pet chewing their paws or licking their rear end. Hot spots, ear infections, itchy, scratchy, lumps, bumps, scabs, and more… What do most of them have in common? Allergies.

What Exactly is an Allergy?

Much like humans, our pets exhibit allergic symptoms when their body overreacts to a substance that it sees as harmful. When your pet’s body reacts to something (fleas, pollen, food, etc), their immune system creates an antibody known as immunoglobulin E (IgE). Once these antibodies are produced, contact with those particular substances will cause allergic symptoms in our pets, ranging from itching, hair loss, skin irritation, odor, and chronic ear infections.  With allergies being one of the top reasons for a client’s visit to their veterinarian, it is important to know the different and most effective methods of treatment.

Types of Allergies

Food:    Choosing the right food for your pet can seem confusing and complicated. An industry that already touts numerous types of food has become even more perplexing with brands shouting “grain free”, “allergen free”, and “all natural.” At the first sign of skin trouble, we see many owners quickly assume that the food their pet is consuming is the culprit. But how common are food allergies in dogs and cats, really?

Dr. Tina Brown is a board-certified dermatologist and a Diplomate of the American College of Veterinary Dermatology (ACVD). She has extensive experience in the management of chronic skin and ear infections secondary to allergies.

“Food allergies may not be as common as many owners think,” Brown says. “This is especially true in the southern part of the country where environmental allergies are much more prevalent.”

There is currently no reliable clinical testing available to determine if your pet has a food allergy. The best way to diagnose if food is the culprit is by beginning a food elimination trial. It is essential that this trial is done with a diet that contains a single source protein and a single source carbohydrate. Veterinarians prefer these sources to be ingredients that your pet has most likely not had much contact with. Since most of our traditional pet foods are comprised of chicken, pork, wheat, and corn, elimination diets are most effective when composed of novel ingredients. During a food trial, your pet should not consume anything other than the special food that they have been prescribed. Even a small bite of the food that they are allergic to can cause allergic symptoms.

Examples of novel proteins and carbohydrates.

Examples of novel proteins and carbohydrates.

While there are over-the-counter limited ingredient diets, a veterinary prescribed diet goes through rigorous clinical trials and is less likely to suffer cross-contamination during the manufacturing process. A study performed in 2011 confirmed these risks when testing the validity of the ingredients listed.1 The results of this study revealed that three out of the four popular OTC brands tested contained ingredients other than what was listed on their label. For this reason, it is important for owners to purchase a food from a company that provides strict quality control.

Environmental:   The most common allergies seen in our pets are environmental allergies. Pollen (weeds, grasses, trees),  dust mites, and molds are just some of the common allergens that can contribute to your pet’s skin problems. Similar to humans, different parts of the country tend to carry higher amounts of common allergic triggers. Unfortunately, the southern part of the country tends to be the worst. Because allergens are present both in the home and outside, even pets who are strictly indoors can suffer from allergic symptoms.

Symptoms:

When we think of allergies in people, we tend to think of the miserable seasons of runny nose, itchy eyes, and constant sneezing. In dogs and cats, allergies will mostly manifest on their skin, ears, and feet.

“While we do use the term allergies, in pets what we are really dealing with is atopic dermatitis,” Brown says. “While humans tend to have more inhalant or respiratory signs, dogs absorb 85% of their allergens in their skin. This is where we see most of the primary clinical signs.”

Symptoms of allergies in our pets include itching, redness of the skin, chronic ear infections, chronic skin infections (both yeast and bacterial), excessive licking of the paws, and alopecia (hair loss). In cats, allergic symptoms will often manifest in the form of skin lesions and self-inflicted alopecia. Many of these cats are misdiagnosed with a behavioral problem when allergies are in fact the main culprit. It is important for owners to understand that allergy signs and symptoms can manifest together, or independently.

“A pet can have chronic ear infections and yet their skin never appears itchy. Even a pet that solely suffers from ear infections can still be suffering from allergies,” Brown says.

Canine patient with chronic ear infections

Chronic Ear Infections in Canine

Feline with Allergic Induced Skin Lesions

Allergic Dermatitis

Self-inflicted Alopecia

Self-inflicted Alopecia

Treatment:

It is crucial for our readers to understand the difference between managing allergy symptoms, and treating the allergy itself. When allergies occur, our first reaction as an owner is to remove our pet’s discomfort. There are a number of topical and oral medications on the market that will aid in doing so. The important thing for owners to understand is that while traditional therapies can provide immediate relief, they should only be used in the short term while the root of the problem is addressed. While many treatments provide only symptomatic therapy, an allergy desensitization serum (or immunotherapy) is the gold standard in the treatment of atopic dermatitis. Dr. Brown is a huge advocate of this treatment and even uses it on three of her own dogs.

Allergen-Specific Immunotherapy:  A number of studies have revealed that over 60% of dogs treated with immunotherapy have achieved positive results.2,3 This is because instead of masking the underlying problem, immunotherapy essentially changes the way that the immune system responds to the allergens overall. Intradermal skin testing is performed to determine what your pet is allergic to and a serum is developed for them specifically. Immunotherapy has been around for hundreds of years and carries very little long-term side effects with continuous use. While it can take up to a full year for some patients to achieve the full benefit, most owners report a significant change in their pet’s allergies within three to four months.

Intradermal Skin Testing

Intradermal Skin Testing

Symptomatic Therapies:   While immunotherapy is the only medical treatment that will get to the source of your pet’s allergies, there are several medications that can be used in the short term to manage symptoms. For some pets, it can take several months for their immunotherapy to provide substantial relief. In the meantime, there are several medications that can be used to aid in the relief of itching and inflammation.

  • Apoquel®: Apoquel® was introduced to the veterinary industry in 2015. It works by blocking specific proteins that stimulate itch and inflammation. While your pet’s allergy still exists, Apoquel® basically tricks your dog’s brain into thinking that they are not itchy. While the drug does block inflammatory mediators that cause itching, there are many inflammatory mediators at play when it comes to allergies. Since the drug cannot cover all of them, many dogs will still experience allergic symptoms. Apoquel® should not be used in dogs that are less than 12 months of age, have a history of cancer, or suffer from serious infections.  It should be used with caution in the immune-suppressed patient.
  • Cytopoint®: Cytopoint® has a similar mechanism to Apoquel, except that it targets different receptors. It is administered as an injection and can be given every four to eight weeks. Since Cytopoint® cannot target all inflammatory mediators, some dogs will experience allergic symptoms. Cytopoint® carries minimal side effects and can be used on dogs of any age.
  • Corticosteroids: Corticosteroids are commonly known by the names prednisone, prednisolone, or Temaril-P®. They work by suppressing the immune system’s response to allergens and reduce inflammation. Long-term usage of corticosteroids can carry serious side effects. They should only be used in the short term when the benefits outweigh the risks.

“Symptomatic therapies will help an itchy patient, but over a period of time the body can build-up a tolerance and they can stop working,” Dr. Brown says. “No symptomatic therapy is without side effects and is contraindicated in patients with cancer, a suppressed immune system, or recurrent illness. Immunotherapy definitely carries the least amount of side effects and will not suppress the immune system.”

The best way to determine which course of treatment is best for you pet is to visit your regular veterinarian or a board-certified veterinary dermatologist. A thorough history and physical examination can lead your veterinarian to the next best course of action.

 

About Dr. Tina Brown:

Tina Brown DVM, Diplomat ACVD

Dr. Tina Brown a board-certified dermatologist and a Diplomate of the American College of Veterinary Dermatology (ACVD). She specializes in diseases of the skin, ears, and nails due to allergic, parasitic, autoimmune, endocrine, and infectious causes. Brown is a graduate of Auburn College of Veterinary Medicine and completed her dermatology residency at LSU. Dr. Brown has three rescue dogs and three cats. In her spare time, she enjoys visiting her family farm in Alabama and taking her dogs to the outback off-leash park at Shelby Farms.

 

References

1. Raditic DM, Remillard RL, Tater KC. ELISA testing for common food antigens in four dry dog foods used in dietary elimination trials. J Anim Physiol Anim Nutr (Berl) 2011;95(1):90-97.

2. Nuttall TJ, Thoday KL, van den Broek AH, et al. Retrospective survey of allergen immunotherapy in canine atopy. Vet Rec 1998;143:139-142.

3. Colombo S, Hill PB, Shaw DJ, et al. Efficacy of low dose immunotherapy in the treatment of canine atopic dermatitis: a prospective, double-blinded, clinical study. Vet Dermatol 2005;16:162-170

 

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