What are environmental allergens?

Over the course of a dog’s life, the dog is exposed to many different types of potential allergens that are found throughout the world like human dander, cat dander, feathers, molds, insects, dust mites or allergens that are released into the air from various plants (trees, weeds, grasses). Normal dogs have no issues with exposure, but for dogs with a genetic predisposition for allergies, allergy season and even every-day life can be a source of great discomfort and in some cases, severe disease.

When an allergic dog is exposed to an allergen that it is sensitive to, the allergen will trigger the dog’s immune system to overreact and produce an improper or hyperactive immunologic response. This is why allergies are also referred to as hypersensitivities due to an individual’s hyperactive immune response. Dogs with the genetic makeup to develop environmental allergies have immune systems that overreact to the allergens. Within these dogs, there can be multiple different immune processes occurring: production of immunoglobulins against specific allergens, mast cell rupture, histamine release and the production of high levels of chemical immune messengers called cytokines. Each dog suffering from environmental allergies has an individual immune system response; this variability among individuals leads to a variety of clinical symptoms and secondary complications from this disease. The majority of dogs with environmental allergies not only have a hyperactive immune system, but also a poor skin barrier. If you think of the skin as a wall protecting from invaders, dogs with environmental allergies have holes in that wall allowing for more penetration of allergens and a greater risk of secondary infections.

Symptoms

  • Itchy skin
  • Skin infections
  • Ear infections
  • Chewing or licking of paws
  • Skin licking
  • Face rubbing
  • Red paws
  • Red skin
  • Red ears
  • Ear scratching
  • Head shaking
  • Hives
  • Sneezing
  • Skin swelling or edema
  • Conjunctivitis
  • Watery eyes
  • Brown staining on feet or nails
  • Seasonal skin disease
  • Seasonal skin disease that over time becomes constant

Common environmental allergens

  • Dust mites
  • Weed pollen
  • Tree pollen
  • Grass pollen
  • Mold
  • Insects
  • Human dander
  • Cat dander
  • Sheep dander (wool)
  • Feathers
  • Tobacco

Diagnosis

Board certified veterinary dermatologists are the trained allergists of the veterinary profession. Their extensive knowledge of immunology and allergy allow them to guide you in identifying your dog’s potential allergens. A dermatologist will be able to ask you questions and examine your pet to help determine if environmental allergies are contributing to your dog’s disease or clinical symptoms.

A dermatologist/allergist will be able to correctly interpret allergy testing and pick a custom solution of immunotherapy based on local allergen knowledge and cross reactions seen amongst common allergens with the aim of covering the majority of your pet’s major allergies.

There are two methods of determining what your dog’s immune system reacts to:

Intradermal Allergy Skin Testing.

  • This is the gold standard for identifying what allergens cause a reaction in your dog. This is a very similar test to what human allergists perform. Liquid dilutions of allergens are injected within your dog’s skin. The test will be scored based on the size of wheal or hive formation in response to individual allergens. The test results allow the veterinary dermatologist to formulate your pet’s specific allergy serum for immunotherapy and to make recommendations for avoidance of certain allergens.

Blood Serum Allergy Testing

  • This is a blood test for detecting the level of immunoglobulin (IgE) within your pet’s body. High levels can be used to select what to include in your pet’s immunotherapy.

Medical treatments

Medical treatments for environmental allergies:

The only treatment for addressing environmental allergies is immunotherapy, or allergy shots. Allergy immunotherapy works by exposing your dog’s immune system to small amounts of what they are allergic to. This immune therapy is used to teach the dogs immune system to gain a tolerance to the allergens, thus lowering the hyperactive response of their immune system. This treatment is safe with only mild rare side effects.

Types of immunotherapy:

  1. Subcutaneous: a solution of dilute allergens is injected by you or your veterinary team to maintain your pet’s immune tolerance to their allergens. Usually, this therapy is administered every 2 weeks.
  2. Sublingual: dilute allergens are administered by you typically twice per day under the tongue or in the cheek pouch.
  3. Intralymphatic: dilute allergens are given in the hospital directly into a lymph node to stimulate the immune systems response. On average, this is given once a month for the first 6 to 8 months. Then the patient is switched to subcutaneous or sublingual immunotherapy to maintain.

Medical treatments of the secondary clinical symptoms:

There are multiple symptomatic medications that can be used for dogs with environmental allergies to keep them comfortable or aid in blocking reactions. None of these address the allergies themselves.

Medications: These medications make your pet feel better but do not treat the actual disease, just the symptoms associated with the disease.

1. Cytopoint (Lokivetmab) Very Safe, Monoclonal antibody used to block an itch mediator from conducting the itch signal. Will make most dogs stop itching for a few weeks.

2. Apoquel (Oclacitinib) Safe, Janus-Kinase inhibitor used to block the body’s production of immune messengers (Cytokines) involved in itch and to a lesser extent inflammation. Blocks itching quickly for up to 18 to 24 hours.

3. Atopica (Cyclosporine) Mild to moderate side effects, calcineurin inhibitor used for inflammation (swelling, redness) and itching. It targets the white blood cells which lowers the production of immune mediators involved with the symptoms of environmental allergies.

4. Glucocorticoids (Prednisone, Prednisolone, Methylprednisolone, Triamcinolone, Dexamethasone) mild to severe side effects that are dependent on dose and duration. These medications have receptors all over the body and target many aspects of the immune system reducing itching, inflammation and blocking allergic reactions.

5. Anti-histamines (Benadryl, Zyrtec, etc) Very safe. Histamine type-1 (H1) receptor antagonists (block histamine). The majority of dog’s symptoms of environmental allergies do not respond to anti-histamines due to great variability in oral absorption seen in dogs.

Natural remedies you can try at home

Dogs with mild environmental allergies can sometimes be treated with natural remedies such as:

  • Weekly bathing during allergy season
  • Washing paws after going for a walk outside
  • Avoiding triggers for your dog. For example, if you notice your dog gets spots all over their stomach after rolling around in grass, it would be best to have them avoid that behavior or spray them down with water after.
  • Weekly ear cleaning with a mild ear cleanser
  • Washing your dog’s bedding frequently
  • Vacuuming and dusting inside the house frequently
  • Using air purifiers during allergy season and keeping the windows closed
  • Avoiding insect bites outdoors

Is there a cure for environmental allergies?

For some dogs, immunotherapy is a cure for allergies as long as they continue to receive their immunotherapy. Based on literature, about 5-10% of dogs with environmental allergies can be cured within a few years of immunotherapy; they will no longer need to receive allergy shots. Allergy shots typically start working to reduce the clinical signs of environmental allergies in three to eight months. However, there are some cases that respond sooner and others that can take 12 to 14 months. Unfortunately, there are also some cases, due to many complicated factors, that do not respond to immunotherapy.

Managing a dog’s environmental allergies can be a lifelong process, and in some cases a dog will need the use of immunotherapy, different oral medications, ear medications/cleaners, anti-itch therapeutics and various medical shampoos. Many dog’s allergies can be managed with the right minimal interventions, while others may respond best to a more aggressive approach. We advise developing a plan that will be effective throughout the different seasons to keep your dog as comfortable as possible. Once you, the dog owner, are taught how and when certain therapies are needed, you can avoid more serious allergic flare-ups.