Meadow View © All Rights Reserved.  Privacy Policy | Terms of Use

Looking After  Your Pets Health

590 Lark Street

Geneva, IL  

630 232-8868


Meadow View Veterinary Clinic Veterinarian Batavia, IL

Allergies

Allergies in dogs are a very common problem. Unlike people that develop sneezing and sniffling with allergies, most dogs develop itchy skin. This is potentially related to where histamine and other inflammatory substances are released within the body in response to an allergen (a substance that results in an allergic response). The degree of signs will vary with each patient. Not all patients are allergic to the same substances. Likewise, not all allergens are located in all geographical areas, so a patient may do well in one area, but upon moving may become allergic. The majority of allergens are dusts, pollens, wool, etc. The most common allergy in pets though, is to fleas, (the allergy is actually to the saliva from the flea bite). This makes flea control imperative in any allergy patient. Inhaled allergens are the next most important cause of allergies, (referred to as atopy) then food allergies. Patients with allergies are also more prone to secondary skin infections, (pyoderma) and to ear infections (otitis). Below is more information and things to consider in your pet:


Diagnostics

      History

           When did your pet first develop itchiness?

                     Dogs less than 1 year of age may be more likely to have mites, food allergies or                         other causes of  itchiness

              Did itching develop after moving?

              What time of year is your pet itchy?

                  A pet that is only itchy in the spring, summer or fall may only be itchy outdoor                   pollens, while a pet that is itchy in the winter or year-round may have more                   indoor allergens, multiple allergens or have food allergies.

           Do other pets in the house itch or do you itch?    

                    If you and other pets are itchy, scabies and ringworm must be ruled out

                    If just the pets are itchy, make sure fleas are not the problem, this is the #1

                        cause of allergies in dogs and cats

      Physical Exam  

            A thorough physical exam is an important diagnostic tool for ruling in or out                 certain conditions

                    Is the skin oily?

                     Is there crusting or severe seborrhea?

                    Are there pustules or papules?

                    What body areas are affected?

                Is self-trauma evident?

                Are the ear tips and distal limbs worse than other parts of the body?   

                Any moving mites, fleas ticks or other parasites found?

      Cytology

            A sample of the crusts and oil on the skin is examined under the                 microscope to look for bacteria or yeast that can complicate allergic pets.

      Skin scrape

            This helps to rule out scabies, this mite is difficult to find and may

                 warrant empirical treatment with revolution or ivomec.

      Response to therapy

            Response to antibiotics or cortico-steroids can help diagnose atopy.  The majority                       of pets with allergies will respond very well to cortico-steroids.

      Skin biopsy

            Confirms an allergic type reaction

               Rule-out other disease like pemphigus

               Does not diagnose what pollen, mold etc the pet is allergic to

                Strongly recommended in cases that do not respond to traditional therapy.

      Allergy testing

           Determine what allergen is affecting the pet

              Not all allergens can be tested for

              If an allergen is found, a serum is given by injection on a routine interval (usually

                  weekly)

              Between 65% to 75% success rate (this figure varies)

              Are not effective for determining food allergies

              The patient should be off all medications prior to testing, preferably

              Generally wait until the patient is 1 year old to get exposure to a full season of

                   allergies

         Types of Allergy Testing  

            Blood tests (RAST or ELISA)

              A blood sample is sent to a laboratory to screen for antibody (IgE) to specific

                     allergens

                 Simple, can be ran by any hospital

                 Results may not correlate quite as well as IDST

         Intradermal skin testing (IDST)

            Samples of allergens are injected in a grid pattern just into the skin on a

                   patient

                Exaggerated response indicates an allergy to a specific allergen

                Usually performed upon referral to a specialist

               Much discussion ongoing about value versus blood tests

               Usually more expensive

               Sometimes a combination of the two may be required in difficult cases


      Dietary trial

           Must be with a food the pet has not been exposed to or a low molecular size

                    diet

              Home cooked diets are preferable, but often difficult for many owners to             

                   perform

              Many diets are available, but no single one may be the correct in a given patient

              Give only the exclusion diet, absolutely nothing else (NO Treats)

              Must give at least 8-12 weeks to have a positive effect

Therapy

      Corticosteroids

          Very effective for most atopic allergies

             Effective treatment for the patient that is only itchy for a few weeks or so each                        year

             Side effects if used chronically at high dosages

             Increased drinking and urination

             Iatrogenic Cushing’s

             Thinning of the skin

             Liver disease

             Predispose to secondary infections

             Muscle loss

             Not as effective for food allergies

             May not be as effective after long-term use

             Not recommended for long-term use  


      Allergy serum injections (Immuno-therapy)

             Determined based on blood tests or skin testing

             Recommended for pet with chronic allergies

             Injections of dilute amounts of allergen are given to “modulate” the pets immune                   system.  

             This is the only method that does not involve immuno-suppression

             May take 6 to 9 months to see a dramatic response

             Very individualistic treatment, (dosage, frequency, etc)

             About 65 to 75% of patients respond well

             Many patients may still need adjunctive therapy during high allergen seasons

             Very well tolerate, although reactions are rare they can occur

                   

      Atopica

           Antirejection medication used to decrease the immune response

             Well tolerated, but some pets can vomit

  

   Adjunct therapy


      Omega 3 fatty acids

           Omega 3 fatty acids may result in inflammatory mediators

             Help to regulate replication of the epithelial cells

             Help maintain moisture in the skin and follicles, preventing dry skin

             May be more beneficial when used in combination with other therapy

 

      Antihistamines

          Many available, many different responses

             Effective for mild cases in some patients (maybe 30%)

             May help reduce the dosage of other medications (corticosteroids)

             Few side effects


      Bathing/Medicated shampoos

          Delivers medication locally, less chance of systemic side effects

             Help reduce allergen on the patient

             Control bacterial and yeast overgrowth

             Soothes the skin

             Help control oily or dry skin

                     

      Allergies can be a frustrating and difficult condition to control.  There is no “Silver Bullet”, so set realistic goals.  Pets will not be cured of this condition, only controlled!  While everyone would like their allergic pet to itch no more than a normal dog, flare-ups are going to occur.  This is no different than an asthmatic person.  Therapy will be designed to keep your pet as comfortable as possible.  No single therapy is effective in every patient.



Canine Atopic Dermatitis

Diagnostic Checklist

□ Age at onset <3

□ Mostly indoor

□ Corticosteroid-responsive pruritis

□ Chronic/recurrent yeast infections

□ Affected front feet

□ Affected ear pinna

□ Non-affected ear margins

□ Non-affected dorso-lumbar area



This validated checklist is 85% sensitive and 79% specific when dogs meet at least 5 of the 8 criteria.*  It is important to invstigate and rule out alternative or concurrent diagnoses based on the clinical findings.

 

*FavrotC., etal  Vet Dermatology 2010