Stop That Scratching!

Hot spots, ear infections, chewing the feet, generalized itchiness, hair loss, poor appetite, vomiting, diarrhea…what do all of these symptoms have in common? If your Black Russian Terrier shows any or all of these signs, it could mean your dog is suffering from allergies. Allergies are common in the canine species and come in variety of shapes and sizes. Generally, in the dog, we group allergies into the following three categories:

1. Flea allergy dermatitis (FAD)

2. Canine atopic dermatitis (Atopy)

3. Food allergy

While there is no true cure for an allergy, there are a variety of available treatments and therapies to help alleviate symptoms and keep your best friend more comfortable.

Flea Allergy Dermatitis (FAD)

Depending on where you live, fleas may be a minor seasonal nuisance or a year-round pest that is difficult to eradicate. While some dogs don’t seem bothered by the occasional flea or two, dogs with FAD are hypersensitive to the flea’s saliva. This means that getting exposed to as little as one or two fleas can cause severe generalized skin disease. Pruritus (itching) is usually generalized (meaning all over) and often accompanied by a secondary skin infection that intensifies itching. A dog may encounter hair loss – the most common area being over the rump – as well as areas of excoriation (scratches, broken hairs), pustules (indicative of bacterial infection) and flea dirt. Dogs with fleas also have a high risk of tapeworm (Dipylidium caninum) infection, as the flea is the intermediate host of the tapeworm.

Treating flea allergy involves a three-pronged approach:

1. First, treat the patient. This includes medicine to kill and/or repel fleas. Many products are available, so it is best to consult your veterinarian for a recommendation. If your dog is suffering infection or severe pruritus, sometimes corticosteroids, antihistamines and antibiotics are prescribed to alleviate itching and treat infection. To effectively eliminate a flea infestation, all animals housed together should be treated with a flea preventive.

2. The second task involves treating the premises. Fleas have a very high reproductive potential, reproducing quickly and effectively. Decontaminating the environment is a must as the environment contains hundreds or thousands of flea eggs, larvae and pupae, waiting for the opportunity to hatch and re-infest your dog. This step may include area treatments, such as flea bombs or sprays, often containing an insect growth regulator (IGR) to prevent future flea eggs from hatching. If you choose not to use chemicals in your home environment, washing of all bedding and thorough regular vacuuming can also be effective in eliminating flea eggs and larvae from the environment. You need to be diligent with this task. Vacuuming once will not likely resolve the problem. Vacuuming daily to every other day will likely be required to effectively eliminate the pests. In severe infestations, seeking help from a professional exterminator should be considered.

3. The third aspect of flea control is not as easy, especially if your dog likes to travel to a lot of places. This step involves decreasing fleas in the outdoor environment, thus reducing your dog’s exposure to fleas. If you have a yard, regular treatments with insecticides can help reduce flea numbers. Focus on shady areas, such as under decks and around trees and shrubs. Fleas do not live in hot, non-shaded areas, so if desired, these areas need not be treated. There are a number of natural remedies that can be effective in decreasing flea numbers in outdoor environments. Spreading nematodes, which eat flea larva and other pests, for example, can be a successful alternative to traditional pesticides. For a more thorough list of natural remedies for flea control, I suggest chatting with a veterinarian versed in complementary alternative medicine (CAM), who can give you a better idea of what may work for you.

The bottom line: Be proactive rather than reactive. It is much easier to prevent a flea infestation than react or try to eliminate it. Where I practice in the southeastern United States, I recommend year-round flea control due to a lack of sustained winter weather. I see flea infestation situations here at all times of the year. In more northern climates, year-round flea treatments may not be necessary. My BRTs take Trifexis®, a monthly oral flea and heartworm preventive that I have found to be extremely effective in eradicating fleas and treating/preventing flea infestations.

Canine Atopic Dermatitis (Atopy)

Atopy, also known as allergic inhalant dermatitis, is perhaps one of the most common maladies I treat in everyday practice. Atopy is a genetic disease, characterized by hyper sensitization to one or more environmental allergens. This is manifested as chronic, sometimes severe itchiness, often with secondary infection present. Itching may be generalized or localized to certain areas, causing things such as otitis externa (ear infection), pododermatitis (infection of the bottom of the feet) and hot spots (deep skin infections). Rhinitis (infection that mostly affects the nasal cavity and sinuses) and conjunctivitis (sometimes called red eye or pink eye) may also be seen.

Atopy is estimated to have an incidence rate of approximately 15 percent. It can occur in dogs of any age over 6 months but will often begin in relatively young dogs 1 to 3 years of age. It is usually seasonal, although in time it may progress into a non-seasonal occurrence. The mode of inheritance is unknown and likely multifactorial. As well, geographic location can have a great influence on atopy. In the United States, the Southeast is a hotspot for canine (and human) allergies. Common allergens involved with atopic dermatitis include pollen (by far the most common offender), dust (house dust mite to be exact) and mold spores.

The atopic dog becomes sensitized to offending allergens over time. Future exposure, whether inhaled or through percutaneous (through the skin) absorption, then brings about an abnormal immune response to the allergen leading to inflammation, itchiness and often secondary bacterial or yeast infection. The most common areas affected include ear canals, muzzle, around the eyes, the feet, axilla/groin and perianal region.

How is atopy diagnosed? Often, clinical signs and past history, such as seasonal skin infections, are used to determine if atopy is present. Tests, such as skin scrapes, fungal or bacterial cultures, may also be used to rule out other potential causes of pruritus. It is important to be sure fleas are not present, as flea allergy dermatitis can look very similar to atopy. Food allergy (covered in the next section) can also mimic atopy in dogs.

Advanced testing to confirm atopy can also be performed. This includes allergy testing. Unfortunately, allergy tests are not always accurate. The most common allergy test performed in small animal practice is the immunoglobulin E (IgE) blood test. A blood sample is drawn and sent to a lab. The blood is then tested for reactions to regionally specific allergens. From this, deductions are made as to what the dog is allergic. The accuracy of these tests is sometimes called into question.

The intradermal (scratch) test can also be performed and is considered by most to be more accurate. This is the same test human dermatologists use. Unfortunately, due to expense and short shelf life of the allergen extracts needed for this test, it is often only performed at referral dermatologist offices. Sometimes the IgE blood and intradermal test are used together to best determine to what a dog is allergic.

Treatment of atopy: As previously mentioned, there is no cure for allergies. This is true in both humans and dogs; however, there are ways to help alleviate symptoms and manage the disease:

1. Reduce contact with offending allergens: This may include regular bathing with soothing shampoos (aloe/oatmeal) to help decrease transdermal exposure to allergens. Keeping your dog indoors during heavy allergy season (assuming a pollen allergy) may help as well. Also, running your house A/C fan and regularly changing the filters may help reduce dust and pollen in the air.

2. Treat secondary skin and ear infections with appropriate course of antibiotics and/or topical medications (lotions, sprays, medicated shampoos). Secondary infection is a huge contributor to continued pruritus and must be addressed and eliminated.

3. Prevent allergic reaction to decrease inflammation and itching: This is accomplished with a variety of medications. For short courses of treatment, corticosteroids are rapidly effective and highly potent in eliminating the allergy cascade that leads to itching and infection. However, corticosteroids can cause a lot of secondary side effects and are not good as a long-term treatment option. A ‘pulse’ treatment of two to three weeks of prednisone is highly effective in getting most dogs through a bad allergy flare-up; however, if treatment is required for longer than this, alternative treatments should be explored.

Antihistamines (diphenhydramine, hydroxizine and chlorpheniramine) can also be used but are not always effective in eliminating the itching/inflammation cascade in canine atopy. Newer antihistamines, such as ceterizine (Zyrtec®) and loratidine (Claritin®) have shown to be somewhat more helpful, with a positive response in approximately 20-30 percent of atopic dogs. Long-term antihistamine therapy can be tried as an option to control atopy but is not always very successful.

1. Desensitize the dog to allergens: If allergy testing has been performed, allergy shots can be formulated to desensitize the patient to the offending allergen(s). This is similar to allergy shots given to humans. Small doses of allergen are injected into the dog at regular intervals in an attempt to desensitize the immune system to allergens. This method of controlling allergies in dogs is not as popular as it was in the 1990s, likely due to expense and a perceived lack of efficacy of the allergy shots. Remember, allergies cannot be cured, only controlled. Allergy injections will often make a very itchy dog less itchy, but still itchy nonetheless. This can bring about frustration in a dog owner expecting the shots to cure the dog from itching. It should still be considered for dogs requiring long-term allergy control because decreasing the severity of symptoms makes the dog more comfortable. Along the same lines, oral allergen drops are being developed to replace the injections, making home treatment easier for the owner.

2. Immunomodulation with cyclosporine: Cyclosporine (marketed as Atopica®) can be used for dogs with extreme allergies that tend to occur throughout the year, or over long stretches of time. Due to the chronic nature of the allergy in these dogs, prednisone, as mentioned, is not a good long-term choice for treatment. Chronic prednisone use can lead to increased thirst, appetite, urination, weight gain, adrenal hypoplasia and liver issues. Cyclosporine, an immunomodulator, is very effective at blocking the allergy cascade and does not have the secondary hormonal side effects seen with chronic prednisone use. The main drawback of cyclosporine use is expense, especially for a large dog. Also, it may not be strong enough in acute severe allergy flare-up situations, thus often necessitating an initial treatment with corticosteroids to get the dog better before using cyclosporine to maintain long-term comfort.

3. Additional therapies: There are a lot of complementary treatment options that can also help the atopic patient. Increasing or supplementing omega 3 fatty acids (commonly found in fish oil capsules) in the diet can be beneficial. A topical triglyceride product marketed by Virbac® as Allerderm® can be used to repair breaks in the lipid layer of the skin and help decrease transdermal allergen penetration. Also, medicated shampoos can be used to target the secondary bacterial and yeast infections, or the greasy skin (seborrhea) often seen with atopic patients.

Atopic dermatitis requires lifelong treatment and management to maintain a comfortable dog. Through a variety of treatment options, good control can be attained for most dogs. Each dog is unique, so long-term treatment options need to be tailored to specific needs. Regular evaluations of treatment efficacy, and in some cases lab work to monitor long-term drug use side effects, should be included in a successful atopy control program.

Food Allergy

Food allergies in the canine can come in either dermatologic or gastrointestinal (GI) forms – or both. Common GI maladies associated with food allergies include such symptoms as vomiting, diarrhea, poor appetite and the inability to gain weight, among others. This article, since we are primarily dealing with itching, will focus on the dermatological manifestations of food allergies.

What exactly is a food allergy? A food allergy is defined as an abnormal immune response by the body to an ingested food or substance, producing untoward effects in the body, of which the most commonly seen is pruritus of the skin. This is not the same as food intolerance, which has no immunologic basis (think of lactose intolerance) or an adverse reaction to food, such as in food poisoning.

Food allergy is believed to have a genetic basis with breeds such as the Labrador Retriever, German Shepherd and several others being over-represented. I have found no references to incidence rates of food allergies in BRTs but know of a few BRTs who are seemingly allergic to something in their diets (one of mine included). Age at onset is extremely variable (4 months to 14 years). It is interesting to note that many cases occur at a very young age (less than 1 year). The most common sign of food allergy in dogs is a non-seasonal chronic pruritus that can be generalized (all over) or localized to certain areas, with feet, ears and the rear being the most commonly afflicted areas.

Inflammation produced by an allergy often leads to secondary bacterial or yeast infections of the skin and ears. Sometimes thinning of the hair (alopecia) is evident, as well as body odor. A dog may scratch, lick or chew at affected areas. Inflammation or infection is usually much less responsive to treatment by corticosteroids than with canine atopic dermatitis.

Food allergies tend to take time to develop, often over several months. It is important to remember the dog has become or is becoming allergic to a certain ingredient and not the entire diet. Thus, switching food brands often will not resolve a food allergy. Also, if a dog has become allergic to a substance in the diet (i.e., chicken), the dog will be allergic to that ingredient no matter how it’s prepared (i.e. kibble, raw or home-cooked).

How are food allergies diagnosed? If you suspect food allergy in your dog (non-seasonal pruritus with poor response to standard atopy treatments, with or without other GI symptoms) – what should be done to confirm the diagnosis and treat the condition? First, there is no simple test for food allergy. There is an immunoglobulin A (IgA) blood test on the market for testing, but it has consistently failed to provide accurate results and is rarely, if ever, recommended. So the first step is to ensure no other factors are causing itchiness. This may include treatment for fleas or mange, or antibiotics or antifungals to clear up any secondary infection. Once step one is complete, and assuming no other cause of the pruritus is uncovered, a food trial is often performed to determine if the dog truly has a food allergy.

There are generally two food trial options most often performed:

1. The first is using a limited ingredient, novel protein diet – the theory being, if we can use a diet with only a few ingredients, and with ingredients the dog has never eaten before (and thus has not had a chance to develop an allergy to them), then the dog’s skin condition and GI problems if present should clear up on the limited ingredient food. The most commonly used limited ingredient diets are fish/potato- and venison/potato-based foods. It is highly recommended that owners seek these foods from a veterinary professional, as a lot of over-the-counter limited ingredient diets are truly not suitable for a food trial due to cross contamination of other ingredients at the manufacturing level.

2. The second food trial involves an immunologic approach using a hydrolyzed protein diet, for example, Hills Z/D® or Royal Canin® Hydrolyzed Protein HP. These are chicken-based diets (and chicken is a common reactor) but the protein molecules are hydrolyzed into very small particles. These small proteins are too small to trigger an immune response and thus the allergic reaction to the food is avoided.

In either situation, when performing a food trial, one has to dedicate at least 10-14 weeks to the trial before determining if it is effective. Sometimes a second trial using a different food may also be suggested if no response is achieved to the first. Also, it is imperative that the dog eat NO other foods or treats during this time so as not to interfere with the food trial. At the end of the trial, if the response is favorable, then food allergy has been confirmed. If the response is questionable, a feeding challenge can be instituted (return to the old food for a few weeks) to see if conditions deteriorate – and if so, a food allergy is also likely.

The most commonly identified canine food allergens are, in descending order: beef, dairy, wheat, chicken, lamb, soy and corn. It should be noted that true food allergy is not common, with an estimated incidence rate of approximately 5 percent of dogs presented for pruritus.

In conclusion

Any of the above three disorders – flea allergy, atopy or food allergy – can produce an itchy dog with secondary skin infection. Sometimes it is not easy to determine the underlying etiology. Plus, there are many other causes for itching aside from allergies, such as contact dermatitis, demodectic or sarcoptic mange, fungal or primary skin infections, and immune diseases, among other issues.

If you are faced with an excessively itchy dog, visit your veterinarian for an evaluation so that a complete skin work-up can be performed to try and determine the best course of action and treatment for your BRT.

I hope this article has been helpful. Information on other health issues is found in our article called Health Concerns in Black Russian Terriers.