more info allergies


Allergies in pet

Unfortunately, just like people, pets can have allergies, too.  Predisposed dogs inhale, ingest or absorb through their skin allergens that provoke an allergic response. An allergen is any substance or material that can cause an allergic reaction in a patient. The allergen, a protein, indirectly stimulates mast cells in the skin, gastrointestinal and/or respiratory tract. Once stimulated, mast cells release histamine and other inflammatory substances to evoke an allergic response. The allergic reaction can occur within a few minutes, hours, or days after exposure.  Some examples of allergens are: tree and grass pollens, wool, mold spores, house dust, flea saliva, and protein in food (beef, dairy, chicken, eggs and wheat).


  • The age of clinical onset is usually between 6 and 24 months but can suddenly occur in older pets, too.
  • Pets allergic to allergens found in the environment (grasses, tree pollen, house dust, mites or/and weeds) frequently show dermatological signs—such as scratching their ears, sides and between legs; rubbing their face; and licking their paws and anus.
  • It is not uncommon for allergy pets to develop secondary skin infections where they itch. It is speculated that over 50% of reoccurring ear infections are triggered by allergies.
  • Some allergy patients show respiratory signs – such as red eyes, clear runny nose, dry cough and sneeze.
  • Pets with food allergies usually itch around the head and neck area; chew paws, and lick anus. Surprisingly, gastrointestinal symptoms, like vomiting and diarrhea, are NOT present in every food allergy pet.  Pets can develop food allergies to ingredients that they have been ingesting without symptoms for months to years before showing signs of food allergies.
  • The neurologic manifestation of allergies may be depression, irritability, and extremely rare, seizures.
  • Pets with environmental allergies may initially show clinical signs seasonally, but eventually 70% or more of the allergic dogs progress to non-seasonal signs. 75% of the allergic dogs will initially manifest symptoms in the spring to fall period and 25% in the winter.
  • Pets with Flea Allergy Dermatitis (FAD) are allergic to the protein found in the saliva of fleas. When a flea bites your pet, it injects its saliva underneath their skin. Classic symptom of FAD is intense itching around the base of the tail and hindlimbs.

Many dogs are allergic to more than one allergen.  Some dogs have a combination of food allergies and environmental allergies making diagnosis and control more difficult.  In many cases, alleviating one allergy will make the second one more controllable.


First, a detailed history of your pet’s dermatological problems will be taken: including age of onset, seasonal occurrence, and where they itch.  Next, a thorough physical examination will be performed.  The veterinarian may also consider non-allergic causes of pruritis, like skin mites (Sarcoptes or Demodex), bacterial or fungal infections, and/or autoimmune diseases.  A skin scrape may be performed to look for mites. A bacterial or fungal culture may be performed to look for bacteria or fungi. A skin biopsy may be performed to rule-out an autoimmune disease.  Mites and fleas are sometimes difficult to find on your pet’s skin, and sometimes we may treat with an itchy pet with one without confirmation of their presence.  A positive response to an insecticide highly suggests the cause of your pet’s itchiness was mites and/or fleas.

Pets with food allergies have non-seasonal (year-round) allergies.  If a food allergen is suspected, we will place your pet on a veterinary prescription limited ingredient diet for 8-12 weeks.  The objective is to eliminate the offending ingredient from your pet’s diet.  Frequently, we will recommend a unique protein diet; like duck, fish, rabbit, alligator or venison. These ingredients are not usually found in over-the-counter pet food.  Alternatively, we may recommend a hydrolyzed protein diet – a diet where the protein is too small to elicit an allergic response.  The hydrolyzed protein prescription diet is effective in up to 85% of our food allergy patients.

If your pet has food allergies, your pet’s itching should improve over the course of a food trial.

An over-the-counter pet food with one single protein listed on the food label is NOT an acceptable elimination diet.  Frequently, these over-the-counter “single ingredient” pet food diets are unintentionally contaminated with other proteins found on their manufacturing or packaging equipment.

During the feeding trial, no other food (pet treats, table scraps, or edible bones) can be given.   This also means re-evaluating the products you use to prevent heartworm disease, and control fleas and ticks. Many of these routinely recommended products are flavored with meat. We will recommend alternative non-flavored products.

With environmental allergies, the first allergic experience usually coincides with its plant pollination. Two notable exceptions are house dust and house dust mites, which are year-round.  Pets with grass and tree pollen allergies are usually itchy in the spring.   Pets that are itchy in late summer are usually allergic to weeds.  Pets itchy in rainy fall weather are usually mold allergy patients.  In time, however, seasonal patterns may be lost as the patient’s allergies worsen and /or pet may develop new sensitivity to other allergens. Observation of your pet’s skin flare-ups may give us insight into which allergens are problematic. Keep a record of your pet’s itchy times of the year and your pet’s itchy places.

If environmental allergies are suspected, we may recommend allergy testing to determine which allergen your pet is allergic to.  The gold standard test for uncovering which allergen your pet is allergenic to is the Intradermal Allergy Skin Test.   A veterinary dermatologist performs this test. With light sedation, low doses of allergens are injected under your pet’s skin and the reaction is monitored.  Alternatively, we can perform a Heska Northeast Allergen Screen test on your pet’s blood sample to identify which allergens your pet is allergic to.

Neither the Intradermal Allergy Skin test nor the Heska Allergy Blood test is accurate for identifying food allergies. The only way to test for food allergies is by performing the elimination diet trial and then each week re-introducing one new ingredient and watching the pet’s response to it.


Please remember that allergies cannot be cured but can be managed.

  • Avoidance of allergen

If the allergen is known, it is important to try to reduce provocation. Example – if your pet is allergic to fleas, avoid fleas and use good flea control.

  • Keeping the pet’s hair short

A long hair coat may create a “dust mop” effect by collecting allergen particles and providing a continuing source to the patient.

  • Secondary infections

Oral, topical or injectable antibiotics or anti-fungal agents may be given to control secondary               bacterial or yeast infections.  Shampoos or topical sprays containing phytosphingosine-                         salicyloyl and lipacid help strengthen their skin barrier.

  • Cleansing and moisturizing

Dry skin is very irritating to your pet and can predispose the pet to secondary skin infections, called pyoderma.  It is not uncommon that we may recommend a topical moisturizer for your pet to be applied 2 to 3 times per week on your pet’s coat.

Prophylactically, we may recommend bathing your allergic pet with a hypoallergenic shampoo once or twice weekly to rinse off surface antigens clinging to your pet’s fur. Use cool water and leave shampoo on pet’s fur for at least ten minutes before rinsing off.

If your pet has a skin infection, we may recommend bathing your pet TWO to THREE times per week with an antiseptic shampoo containing 2-4% chlorohexidine. If your pet has a yeast infection, we recommend a ketoconazole and chlorohexidine based shampoo.

Cleaning your pet’s feet with hypoallergenic baby wipes may also decrease lingering exposure to outside allergens.

  • Anti-inflammatory drugs

Fatty Acid Supplements – The correct balance of fatty acids can help decrease the skin’s inflammatory response.  Many pet foods companies have added additional fatty acids to their diets, but their dose may be inadequate or their active concentration maybe diminished during the manufacturing process.  A dose of 40 mg EPA per kg of body weight and 25mg DHA per kg of body weight is recommended.  I recommend the triglyceride formulation of fatty acids since they are more bio-available than the manufactured version.   Due to inaccuracies in fish oil products, we recommend the following fatty acid products only : Veterinary Recommended Solutions (VRS available at AMCOC only), Nutramax’s Wellactin (available at AMCOC and online), and Nordic Natural Fish Oil (available at some stores and online).

Antihistamines – this class of drugs works fairly well (up to 50% respond) in patients with mild symptoms.  When it is effective, it reduces the pet’s pruritis and makes them more comfortable.  The major side effect of antihistamines is drowsiness. If this occurs, we may suggest reducing the dose or trying an alternate drug. Do not purchase antihistamines with decongestants – these are very irritating to the pet’s respiratory system. Use the antihistamine for at least 2 weeks before judging whether it is effective.

Apoquel This is a relatively new drug that decreases the release of mediators of inflammation, which trigger our pets, to itch. It is highly effective – almost 85% of our canine patients improve within the first 4 to 24 hours after oral administration. This medication is NOT a steroid and does NOT adversely affect the kidneys, liver or pancreas. It is initially dosed twice daily for the first 10 to 14 days, and then, the frequency is reduced to once daily during your pet’s allergy season. It is not recommended for allergy pets under one year of age.

CytopointThis revolutionary new drug dramatically reduces itching in many of our canine allergy patients by blocking a receptor site on cells that triggers the release of mediators of inflammation.  It is given as a subcutaneous injection by your veterinarian once every 4 to 8 weeks to reduce the itch cycle. It may take a few days to become effective. It can be given to pets less than one year of age and has no significant side effects.

Corticosteroids – This class of drugs works very well in allergy patients. Unfortunately, there are major side-effects, such as increased water intake, increased urination, increased food intake, and can cause diabetes, aggravate liver, heart and kidney disease. Sometimes, the pain and discomfort associated with the pet’s dermatological problems outweigh the disadvantages of corticosteroids and we will dispense them. If your pet is placed on steroids, do not stop the medication suddenly.  Your pet’s body may have become dependent on it, and sudden withdrawal could make your pet sick.

Modified Cyclosporine – this is an oral medication that modifies the body’s immune response. It takes approximately 10-14 days to become effective.  It can be used alone or in conjunction with corticosteroids.  Infrequent side effects of this medication are decreased appetite, diarrhea and vomiting.  It is not uncommon that these initial side effects dissipate over time.  We recommend the trademark product, Atopica, due to its known efficacy and consistent drug concentration.

  • Hyposensitization

This is indicated for patients in which avoidance is impossible, anti- inflammatory drugs are not effective or must be given year-round.  In general, 30% of the pets do very well, 30% have noticeable improvement and 30% do not respond. Hyposensitization failures are more common in older pets. The objective of hyposensitization is to desensitize the pet’s reaction to the offending allergen. It may require weekly injections or a daily oral spray of a specially prepared solution to control your pet’s allergies. This is a lifetime commitment.  Depending on the allergen, a beneficial response may be seen within 6 months or up to 1 year after desensitization has begun. Adverse injection reactions are rare and include intensification of clinical signs for a few hours to few days, local reaction at injection site or/and anaphylaxis.

An allergic pet is an uncomfortable pet.  It is our goal at Animal Medical Center of Chicago to help your pet feel as good as possible.  Please discuss your itchy pet with us.  We believe we can make a difference in your pet’s life.