Immunotherapy for Allergic Pets

injectiontreatmentImmunotherapy or “allergy shots” is used to help with hyposensitization of your pet to the identified allergens. Once the specific allergens are identified by either the intradermal tests or the serum testing, a mixture of the allergens is formulated into an allergy extract. The pet is then given small doses of the allergy extract once a week and the dose is gradually increased over time. Improvement in the allergy symptoms may take 6  months to a year to show an improvement in their symptoms. A good response is found in  60-70% of dogs will show substantial improvement. Some dogs will continue to develop new allergies or may be allergic to a substance not identified which will result in a poor response. Those dogs that do respond can then reduce the amount of cortisone and other medications that have been used to treat their allergies. Allergy injections may need to be given to your dog for their lifetime to help control their allergies. Food allergies can not be treated with the immunotherapy. Once the offending food substance is identified either by allergy testing or food trials, the best way to control food allergies is by not feeding the food to your pet. This will require closely reading all labels of treats and foods to identify the ingredients. For more information on immunotherapy, check out


Oral immunotherapy has been used in Europe for over 20 years and is now available for our pets. SLIT (sublingual immunotherapy) is an easy, effective alternative to allergy injections. The mixture of allergens is delivered in a metered dose under the pets tongue or in the side of the mouth. The starting dose is 3 times a day for every day but over time will be reduced to  3 sprays 6 days a week. An improvement can be seen in 6 months to a year, but some pet owners have reported improvement after 4 months. Each vial lasts for about 4 months and must be ordered through your veterinarian. Oral immunotherapy has made hypo-sensitization of your pet to allergies much easier. For more information on oral immunotherapy, check out


Allergy Testing – Intradermal Skin Testing or Serum Allergy Testing

Some pets with allergic skin disease will respond nicely to the occasional cortisone injection and a round of antibiotics, but for some the itching seems relentless. When the pet’s allergies continue to get worse or become a year round battle, allergy testing and de-sensitization can be a useful diagnostic tool and treatment. However, it is not perfect. False positives, false negatives and cross reaction can occur. The tests available for our pets is the intradermal skin tests and the newer serum allergy testing.

intraderrmal allergy testingIntradermal allergy testing has been the gold standard for allergy testing in both humans and pets for years. To perform the test, the pet must not have had any cortisone or antihistamines for at least 2 weeks prior to testing. The pet is then sedated and an area on their skin is shaved. Small marks are made on the dog and then a small amount of the suspected allergen is injected into the skin. After 20 minutes, the wheal or reaction is then measured and compared to the control histamine injection.  The allergens that created a reaction are then identified.

Intradermal allergy testing is expensive, time consuming and usually done by an veterinary dermatologist. The allergens to perform the tests are expensive for the veterinarian to purchase  and have a short shelf life, so unless the veterinarian is performing the tests on a daily basis, they will probably refer the pet to a specialist to perform the diagnostic testing.

The newer serum allergy testing has made a dynamic positive impact on allergy testing for the general practice veterinarians. This technology tests the dog’s serum for specific IGG or immunoglobulins  (antibodies) that have been identified to react to specific allergens. To test your dog, blood is drawn and sent to an allergy laboratory, such as, and panels are done. Regional panels have identified the most common grasses, trees, molds, etc. that cause allergies in the area that you live. The food panel can identify basic food groups that the dog may be allergic to. Once the blood is analyzed, a report is returned to your veterinarian. The advantage to this allergy testing is that it can be done by any veterinarian, does not require shaving, sedation or a withdrawal of the cortisone prior to the testing. The tests will identify the specific allergen the pet had a reaction and this can be used to order the immunotherapy to help with desensitization of your pet to the allergens. The immunotherapy can be in the form of injections or in a new form, oral allergy drops ( The oral allergy drops have increased client compliance in giving their pet the immunotherapy and in some pets, an improvement in their allergies seems to occur much faster than with injections.

Studies have been done and show that after a dog is 2 years of age or older, there is not much statistical difference between the results of the intradermal testing or the serum testing. This allows more pets to undergo allergy testing at their family veterinarian office and with the new oral allergy drops, pet owners no longer have to give injections to their dogs and are more likely to undergo the immunotherapy. We now offer the serum allergy testing and the oral allergy drops to our patients with allergies.

Ragweed and your Itchy Dog


In October, ragweed is in full bloom and many humans suffer with hay fever, complete with sneezing, itchy eyes and even asthma. Allergies  are an exaggerated response of the immune system to a substance called an allergen. Although a small percentage of our pets respond to an allergen with sneezing, the majority of pets have the histamine receptors in their skin and their reaction to an allergen is different to humans.  The end result is itching, scratching, chewing at their paws, rubbing their face. intestinal upsets or flipping their ears.

The most common types of allergies that affect our pets are:

  • Fleas – One bite of one flea can cause a reaction in an allergic dog
  • Inhalant – Pollen, Mold, House Dust, Mites , etc.
  • Food – Wheat, Milk, Eggs, Chicken, Lamb, Rice, Beef, Pork, Turkey, Soybean, Fish and more.
  • Contact – Kapok, Wool, Sisal, Human Dander to name a few.
  • Bacterial Hypersensitivity – The pet can become sensitized to the secondary bacterial infections caused by the scratching and damaged skin.

Pets can be allergic to many things and once their immune system is fired up each time they are exposed to that allergen, they have a reaction. This then leads to developing allergies to more items and makes the condition harder to control. A clue to what they are allergic to can sometimes be linked to the area of the skin that is itching. As a general rule of thumb if the itching is around the base of the tail and back, it is usually due to an allergy to the saliva of a flea bite. If the pet is chewing at their feet, this is commonly an inhalant allergy such as pollens, molds, trees, and grasses. Food allergies can exhibit with itching on their face or intestinal upsets.

When the dog itches can also be a clue to what they are allergic to. In the spring time, it can be the pollen from the trees and grasses. In October, it is probably the ragweed. Seasonal allergies are more responsive to cortisone to relieve the itching until the blooming season is over, but many dogs that were once seasonal develop more allergies that then become year round. These dogs can develop allergies to inside allergens as well as all the outdoor allergens. If your dog suffers from allergies all year round, more aggressive treatments and diagnostics may have to be done because cortisone cannot be given everyday due to the side effects and anti-histamines, like Benadryl, do not relieve the itching as well as it does for us Humans.

Dogs with allergies suffer with the intense itching and also with secondary problems because of the damaged skin barrier. Bacteria and yeast that normally reside in harmony on your pet’s skin can now invade and infect the skin. The bacteria now produce by-products that can elicit more itching resulting in a vicious cycle. Antibiotics are an important component of allergy treatment in dogs with the secondary infection that results from the intense itching.

Ear infections are also a by-product of allergies. The ear is warm, dark and moist and if the dog has allergies, it may show up in the ears first with flipping of the ears and development of ear infections. Ruptured vessels in the ear flap can lead to an accumulation of blood and a hematoma that may require surgery to repair. Allergies can be a causative agent in chronic ear infections and unless the allergies are dealt with, the ears will continue to be problematic.

The goal to treating allergies includes:

  • Identifying the allergen with allergy testing
  • Treating the infections
  • Repairing the skin barrier
  • Alleviate the itching
  • De-sensitize the dog to allergens with immunotherapy
  • Adding dermal supplements such as Omega – 3 FA to promote healing and reduce inflammation
  • Keeping the ears clean with an ear cleanser to remove debris and dry the ear canal
  • Frequent bathing with medicated shampoos to help repair the skin and remove allergens
  • Blood testing to identify underlying problems such as hormonal imbalances
  • Flea and Parasite Control

Your veterinarian will assist you with a comprehensive, step-wise plan to help you and your pet cope with allergies.  Veterinarian specialists are also available to help tackle the most difficult cases. Valerie Fadok, DVM, PhD, DACVD has joined the staff at North Houston Veterinary Specialists and is one of the top veterinary dermatologists. We are lucky to have her serving the Houston area pets.