Allergies are a prevalent and often distressing issue for dogs, manifesting as persistent itching and discomfort. Fortunately, the field of veterinary medicine has advanced significantly, offering a wider array of effective allergy medicines for dogs than ever before. This comprehensive guide, drawing from the expertise of integrative veterinarian Dr. Julie Buzby, explores the signs, causes, and various treatment options available to help your canine companion find relief.
Dogs can suffer from three primary categories of allergies: environmental, food, and flea allergies. Environmental allergies, also known as atopy or seasonal allergies, are triggered by common allergens in a dog’s surroundings such as pollen from trees, weeds, and grasses, as well as dust mites and mold. Food allergies, or cutaneous adverse food reactions (CAFR), occur when a dog’s immune system reacts to specific ingredients in their diet, with common culprits including beef, chicken, lamb, and wheat. Flea allergies, or flea allergy dermatitis (FAD), are a reaction to the saliva of fleas, meaning even a few bites can cause intense itching. It’s also common for dogs to experience a combination of these allergies, which can exacerbate symptoms and necessitate a multi-faceted treatment approach.
Symptoms of Skin Allergies in Dogs
Identifying the symptoms of allergies in dogs is the first step toward diagnosis and treatment. Common signs include:
- Persistent itching of the ears, leading to frequent infections.
- Excessive licking or chewing of the feet and legs, often due to itchy dog paws.
- Constant scratching of areas like armpits, belly, face, and the base of the tail.
- Red, irritated skin that is susceptible to secondary yeast or bacterial infections, such as pyoderma in dogs.
- Frequent rubbing of the face or body against furniture or the floor.
- Noticeable dog losing hair.
- Development of skin conditions like hot spots in dogs, interdigital cysts in dogs, or furunculosis in dogs.
- Less commonly, respiratory symptoms like a dry cough may occur.
- Vomiting or diarrhea, which can sometimes be associated with food allergies.
These symptoms can significantly diminish a dog’s quality of life, preventing them from fully enjoying daily activities. If you observe any of these signs, consulting a veterinarian is crucial.
Diagnosing Allergies in Dogs
Veterinarians diagnose allergies through a thorough review of your dog’s history, including diet, flea prevention, and symptom onset. A physical examination, with a particular focus on the skin and ears, helps identify secondary infections and affected areas. While there isn’t a single definitive test for allergies, diagnosis is based on a combination of these factors and the response to treatment. Allergy testing is primarily used to identify environmental allergens for the purpose of creating allergy shots, not for diagnosing allergies themselves. Food allergies are diagnosed through a carefully controlled food trial.
Treating Allergy Flare-Ups
A case study of Zachory, a senior Chow mix, highlights the challenges and solutions in managing allergies. Due to pre-existing health conditions, Zachory could not be treated with steroids. His veterinarian prescribed Cytopoint, an injectable immunotherapy that effectively managed his environmental allergy symptoms for about a month per dose without interfering with his other medications.
Understanding the Causes of Dog Allergies
Allergies in dogs are an immune system response. Mast cells, which are concentrated in a dog’s skin, release histamine and other inflammatory substances when they detect an allergen. This triggers a cascade of immune responses, leading to the characteristic allergy symptoms. Environmental allergens can easily enter the body through a compromised skin barrier, explaining why skin and ear issues are so common in allergic dogs.
Top Allergy Medicines and Supportive Therapies for Dogs
1. Antihistamines (e.g., Benadryl, Zyrtec)
These over-the-counter medications work by blocking histamine, a key chemical in allergic reactions. While generally safe, they are often less effective for moderate to severe allergies and are best used preventatively or for very mild symptoms. It’s crucial to use formulations without decongestants, as these can be harmful to dogs.
2. Apoquel (oclacitinib)
Apoquel is a targeted JAK inhibitor that effectively reduces itching and inflammation by blocking specific itch-signaling molecules. It offers rapid relief and is generally well-tolerated, with a lower risk of significant side effects compared to older medications. While concerns about cancer risk have been raised, studies suggest it does not increase cancer occurrence, though caution is advised for dogs with a history of cancer. Apoquel is approved for dogs over one year of age.
3. Zenrelia (ilunocitinib)
Zenrelia is another JAK inhibitor approved in 2024. It targets multiple JAK enzymes to reduce inflammation and itching. Some veterinarians report success with Zenrelia in cases where Apoquel or Cytopoint were less effective. However, Zenrelia carries a “black box warning” regarding potential risks associated with vaccinations, requiring careful timing around immunization. It is also approved only for dogs over 12 months old.
4. Cytopoint (lokivetmab)
Cytopoint is an immunotherapy given as an injection every one to two months. It targets and neutralizes a specific itch-signal molecule (IL-31), providing relief without suppressing the immune system. While it excels at reducing itch, it is less effective at controlling inflammation compared to other options. Its injectable form makes it a convenient choice for dogs that are difficult to medicate orally.
5. Dog Steroids (e.g., Prednisone)
Steroids are potent anti-inflammatory medications that can provide rapid relief from itching and inflammation, making them useful for acute flare-ups or to manage severe ear infections. However, long-term use is associated with numerous side effects, including increased thirst, appetite, urination, muscle wasting, and a higher risk of infections and other health problems.
6. Allergy Shots (Immunotherapy)
Considered the gold standard for environmental allergies, immunotherapy involves gradually exposing the dog to specific allergens to desensitize their immune system. Administered via injection or sublingually, it can take 6-12 months to show full effects and may require lifelong treatment. While effective for many, it has a low risk of reaction and may still require supportive medications.
7. Atopica (cyclosporine)
Atopica is an immunosuppressant that works by blocking T-cell activation, reducing inflammation. It requires several weeks to show full effects and can cause side effects like vomiting, diarrhea, gum overgrowth, and increased susceptibility to infections. It has become less favored as a first-line treatment with the advent of newer medications.
8. Diet Changes (Hypoallergenic Diets)
For dogs with suspected food allergies, a food trial with a novel protein or hydrolyzed protein diet is crucial for diagnosis and long-term management. This involves feeding only the hypoallergenic diet for 6-12 weeks. Strict adherence is necessary, as even small amounts of the allergen can negate the trial’s results. Prescription veterinary diets are recommended over over-the-counter options due to higher purity standards.
9. Essential Fatty Acids (Omega-3s)
Supplements like Omega-3 fatty acids can help reduce inflammation and improve skin barrier function, acting as a supportive therapy alongside other treatments. It may take up to two months to observe benefits, and they are not effective as a sole treatment for allergies.
10. Additional Strategies
- Flea Prevention: Year-round flea control is essential, especially for flea-allergic dogs, as even one bite can trigger a reaction.
- Medicated Shampoos: Regular bathing with medicated shampoos can treat infections and reduce allergen build-up on the coat. Wiping down your dog after outdoor exposure can also help remove allergens.
- Environmental Control: Routine vacuuming and washing pet bedding in hot water can reduce dust mite exposure.
- Topical Products: Products that support a healthy skin barrier, containing ingredients like ceramides or fatty acids, can help prevent allergens from penetrating the skin.
Partnering with Your Veterinarian
Managing canine allergies often requires a collaborative approach between pet owners and their veterinarians. Finding the right treatment plan may involve trial and error, and adjustments may be needed as seasons change or your dog’s condition evolves. Open communication with your vet about feasibility, financial constraints, and your dog’s tolerance is key to developing a successful and sustainable allergy management strategy. Early intervention at the first sign of worsening symptoms is crucial for maintaining your dog’s comfort and well-being.
