Canine allergies : beginner’s guide

Defining canine allergies

Canine allergies are a common but often misunderstood health issue. Like humans, dogs can experience excessive immune system reactions to substances that are normally harmless. These substances, known as allergens, can cause a variety of symptoms, affecting the quality of life of our four-legged friends.

Those allergies occur when a dog’s immune system overreacts to a normally harmless substance, called an allergen. This reaction can trigger a range of unpleasant symptoms. Allergies can be seasonal, environmental, or food-related. Contrary to popular belief, allergies are not limited to itching and can affect multiple systems.


Common types of canine allergies

Dogs can be allergic to a multitude of substances. The most common types of allergies include:

  • Food allergies: Often caused by a reaction to certain proteins in the dog’s diet. Symptoms may include skin itching and digestive issues. Unlike food intolerances, which mainly affect the digestive system, food allergies can cause systemic reactions.
  • Environmental allergies: Also known as atopic dermatitis, these allergies are caused by environmental allergens such as pollen, mold, and dust. Typical symptoms include intense itching, especially around the paws, abdomen, and face. These allergies can be seasonal or persistent, depending on the allergen involved.
  • Insect Bite allergies: Reactions to insect bites, especially fleas, are among the most common types of allergies seen in dogs. Even a single flea bite can trigger an intense allergic reaction, causing extreme itching, redness, and hair loss.


Symptoms and diagnosis of canine allergies

Identifying canine allergiescan be challenging, as symptoms can be similar to other conditions. However, early recognition of allergy signs is crucial for effective treatment and your pet’s comfort.


Identifying allergy symptoms

Canine allergies can manifest in various ways, and symptoms can vary from one animal to another. Here are some of the most common signs to watch for:


  • Skin Symptoms: Skin is one of the first indicators of canine allergies. Signs include excessive itching, redness, rashes, hair loss, and recurrent ear infections. Dogs may lick, chew, or scratch the affected areas, sometimes causing injuries.
  • Digestive Symptoms: Although less common, food allergies can cause digestive symptoms such as vomiting, diarrhea, and excessive gas. These symptoms can be intermittent and vary in intensity.
  • Respiratory symptoms: In some cases, environmental allergens can cause respiratory symptoms like sneezing, coughing, or even asthma, though this is less common in dogs than in humans.


Allergy diagnosis process

Diagnosing canine allergies is essential but can be complex. It requires a methodical approach and a veterinarian’s intervention to accurately identify the responsible allergen:


Thorough veterinary consultation

  • Complete history: The vet will start by collecting a complete history, including the dog’s medical history, observed symptoms, diet, environmental exposure, and any recent lifestyle changes.
  • Physical examination: A thorough physical examination will help identify visible signs of allergies, such as skin issues, irritations, and other relevant symptoms.


Diagnostic tests

  • Skin cytology: Microscopic examination of skin cells to detect bacterial infections, yeasts, or parasites.
  • Skin scrapings: Collection of skin samples to identify skin parasites, such as mites.
  • Intradermal (skin) testing: Injection of small amounts of potential allergens into the skin to observe reactions. It is often considered the gold standard for diagnosing environmental allergies.
  • Blood tests: Blood samples can be analyzed to detect antibodies against specific allergens, useful for diagnosing both food and environmental allergies.
  • Skin biopsies: In some cases, skin biopsies may be necessary to rule out other skin conditions.


Elimination diet for managing food allergies

The elimination diet is a critical diagnostic method for identifying if a dog has a food allergy. This process involves several crucial steps to determine the specific food allergens affecting a dog.


Elimination diet

  • Food selection: The diet starts by selecting a protein and carbohydrate source the dog has never consumed before. This approach, called the “elimination diet,” relies on using new ingredients for the dog’s immune system, thus reducing the risk of an allergic reaction.
  • Diet duration: The elimination diet is typically maintained for 8 to 12 weeks. This period is crucial to allow the dog’s immune system to “reset” and to observe a potential reduction in allergic symptoms.


Monitoring and evaluation

  • Symptom tracking: During the diet, it’s important to closely monitor any changes in the dog’s symptoms. A significant improvement in allergic symptoms may indicate that the food allergen has been eliminated from the diet.
  • Regular veterinary consultation: Regular consultations with the vet are recommended to assess the diet’s effectiveness and to ensure the dog’s nutritional needs are still being met.


Gradual reintroduction

  • Sequential introduction of ingredients: After the elimination period, ingredients are reintroduced into the dog’s diet, one at a time. This allows for the specific identification of which ingredient causes an allergic reaction.
  • Observation of reactions: After each reintroduction, a period of observation is necessary to monitor the possible reappearance of allergic symptoms. If a reaction occurs, the reintroduced ingredient is likely the allergen.


Treatments and management of canine allergies symptoms

Once an allergy is diagnosed in a dog, the goal is to manage symptoms and prevent future reactions. There are several treatment approaches, as well as essential prevention strategies.


Different treatment options for canine allergies


  • Antihistamines: These drugs are used to reduce itching and other allergic symptoms. They are considered very safe but are often ineffective when used alone.
  • Corticosteroids: Prescribed for their potent anti-inflammatory effect, these drugs are useful in cases of severe allergic reactions, but long-term use can lead to undesirable side effects.
  • Apoquel (Oclacitinib): This medication works by inhibiting specific signaling pathways (notably JAK cytokines) involved in allergic and inflammatory reactions. Unlike other treatments such as corticosteroids, Apoquel offers the advantage of controlling allergic symptoms without the usual side effects associated with steroids. It is effective for both short and long-term control of allergies in dogs and acts quickly.
  • Cytopoint: This is an injection that helps control itching associated with skin allergies by neutralizing a key protein involved in the transmission of the itching signal. The major advantage of Cytopoint is that it offers long-lasting relief from itching, with effects lasting from 4 to 8 weeks after a single injection.
  • Atopica (Cyclosporine): This medication is used to treat atopic dermatitis. Atopica works by modulating the dog’s immune response, which is useful for reducing allergic skin reactions.
  • Immunotherapy: This method aims to gradually desensitize the dog to specific allergens, offering a long-term approach to managing allergies.


Alternative therapies

  • Supplements: Omega-3 fatty acids and probiotics are often recommended to strengthen the skin barrier and reduce inflammation.
  • Acupuncture: This complementary therapy can be considered to relieve allergy symptoms in some dogs.


Skin care and hygiene

  • Medicated baths: The regular use of special medicated shampoos can help manage skin symptoms and reduce skin infections.
  • Regular skin care: Keeping the skin clean and moisturized is essential to prevent secondary infections.


Prevention of canine allergies and symptom management

Environmental control: Minimizing exposure to household allergens like dust, pollen, and mites is crucial. This may include changes in the household, such as using high-quality air filters and regular cleaning.

Diet and nutrition: After identifying food allergens, it’s important to avoid including them in the dog’s diet. Opting for hypoallergenic or specially formulated foods can be beneficial.

Regular monitoring and veterinary visits: Regular checks with the veterinarian are essential to monitor the dog’s allergic condition and adjust the treatment plan as needed.

Dog owner education: Understanding potential allergy triggers and being able to recognize the early signs of an allergic reaction are important skills for dog owners. Greater awareness allows for effective management and prevention of allergic episodes.


In the end, dog allergies are complex conditions that require thorough attention and understanding. As we have explored, the accurate diagnosis of allergies is a crucial step, requiring specialized tests and careful observation. With advancements in treatment options, it is now possible to effectively manage allergic symptoms, significantly improving the quality of life for our canine companions.

It’s essential to remember that each dog is unique, and what works for one animal may not be suitable for another. Therefore, close collaboration with an experienced veterinarian is indispensable for developing a personalized and appropriate treatment plan for each dog’s specific needs. Additionally, dog owners play a crucial role in managing their pet’s allergies, by monitoring symptoms, adapting the environment and diet, and following their veterinarian’s advice closely.



Version Française ici!