How Does Dog Allergy Testing Work?

If your dog suffers from itchy skin, ear infections, or digestive issues, your vet may suggest allergy testing to determine which allergens cause a negative reaction. Your vet performs dog allergy testing using intradermal skin or RAST blood testing. Both can be beneficial for discovering the cause of your dog's symptoms. But how do dog allergy tests work, and is it the right option for your beloved pet? 

• Symptoms Of Allergies In Dogs
• Causes Of Allergies In Dogs
• Diagnosis & Dog Allergy Testing
• Treating Dog Allergies
• FAQs
• Final Notes

Symptoms Of Allergies In Dogs

Dog allergies are more common than you might think. While it's normal for dogs to scratch themselves occasionally, your pet scratching themselves excessively may indicate they need an allergy test. Itchy skin is the most common symptom of allergies in dogs. However, it's not the only one. If your dog has allergies, they'll show the signs of an allergic reaction with a range of symptoms that might include:

• Itchiness and rashes
• Swelling of the face, ears, lips, and eyelids
• Inflamed skin
• Diarrhea & vomiting
• Sneezing
• Itchy ears 
• Ear infections¹

Causes Of Allergies In Dogs

There are three types of allergies, and the symptoms can overlap, making it difficult to determine exactly what your dog is allergic to. Skin allergies, also known as dermatitis, are the most common allergic reaction in dogs resulting in itchy skin.¹ 

Unfortunately, your dog's scratching and licking to relieve some of their discomfort can lead to secondary infection if they break the skin.¹ With a skin allergy, dogs can be allergic to fleas, food, and environmental allergens that cause itchy skin.

• Fleas: Many dogs are allergic to flea saliva and bites, which causes localized itchy skin where the fleas bite. You may notice flea bites in one location or all over your dog, especially on the ears, rump, and belly. Luckily, flea allergies are easy to identify because you may see fleas crawling on your dog, and your vet can easily diagnose them with fleas and provide fast-acting treatment. 
• Food: Dogs can also be allergic to ingredients in their food, with reactions that include hives, itchy skin, swelling, and GI issues like diarrhea. Food allergies develop over time, so your dog might try new food and not react until they've had prolonged exposure to the allergen. Dogs with true food allergies are at risk of anaphylaxis. However, dogs can also have food sensitivities that result in similar symptoms to allergies, such as ear infections and itchiness.¹
• Environment: Environmental allergies, also known as atopy, is caused by allergens in your home or the environment where your dog spends their time.² These allergies can be seasonal or year-round, depending on what causes your dog's allergic reaction. Common environmental allergens include pollen, dust, mold, and smoke. 

Diagnosis & Dog Allergy Testing

If your dog experiences allergy symptoms, your vet will rule out other non-allergic diseases that can cause similar reactions. They may perform various tests to ensure your dog isn't suffering from another underlying health problem. 

Dog allergy testing isn't used to diagnose dogs with allergies; instead, it's used when your vet has already diagnosed them with allergies to determine the cause of their adverse reactions. Some types of dog allergies are easier to diagnose than others. For example, vets can easily diagnose fleas by visual confirmation or skin testing.  

Dog allergy testing can be useful for determining which allergens cause your dog to react. While you can't prevent your dog from coming into contact with all allergens, these tests can help your vet find the right treatment. 

Dog allergy tests can determine whether your dog is allergic to the following:

• Pollens
• Dust
• Mold
• Fleas³

Unfortunately, while there are dog food allergy tests, it's widely considered unreliable and inaccurate.¹ Therefore, if your vet believes your dog is allergic to their food, they may try an elimination diet. An elimination diet slowly removes individual ingredients from your dog's diet while you and your vet monitor their symptoms to determine whether they're improving. Once your vet has ruled out food allergies and underlying illnesses, they can begin allergy testing for dogs, which may consist of a blood test, skin test, or both. 

Intradermal (IDAT) Skin Testing

Intradermal skin testing performed by a dermatologist can help vets determine the cause of atopic dermatitis. This testing is done under anesthesia, so it might not be the right option for all dogs. During this procedure, your dog is injected with various allergens under the skin to determine if they have a positive response to an antigen, which will show visible swelling. If there is no swelling, your vet will assume your dog has no allergy to that particular allergen. Vets will perform around 60 injections and look for visible reactions at each site to determine what's triggering your dog's allergic response.³

Intradermal skin testing is one of the most accurate methods for determining what your dog is allergic to. However, it's often more expensive than blood testing, and many pet parents don't want to sedate their dogs when they don't have to.  

RAST Testing

Radioallergosorbent (RAST) testing is another option. Instead of using anesthesia and injecting your dog with potential allergens, vets can take a blood sample to determine whether your dog is allergic to certain antigens. RAST testing is more affordable than IDAT skin testing and doesn't require anesthesia, making it a better option for most pets and owners. Once your vet draws your dog's blood, they'll send the sample to a lab for analysis. Unfortunately, RAST testing has a higher rate of false positives than skin testing. That said, the results of these tests can still help you make better decisions for your pet.

Depending on your dog's symptoms, your vet may suggest doing both types of dog allergy tests to provide you with the most accurate information about your dog's allergies.³ It's important to note that dog allergy testing may only be beneficial if you use hyposensitization treatment in which your dog receives a small amount of the allergens to build up a tolerance to them. However, if you don't plan on pursuing it, allergy testing for dogs may not be worth it. 

How Much Does Dog Allergy Testing Cost?

The cost of allergy testing for dogs varies based on your location, vet, and various other factors. However, intradermal skin testing is generally more expensive because it requires more time and sedation. You can expect to pay around $275 to $350, but other than the testing, you should consider the overall cost of diagnosing and treating your dog's allergies.³ Treatments, follow-up visits, and additional testing to rule out underlying health problems will cost much more when added together. 

You can learn more about the costs by talking to your vet. Before they can begin allergy testing, they'll inform you of the basic costs to help you make the right decision for your pet. 

Treating Dog Allergies 

Dog allergy tests can improve the effectiveness of your dog's treatment. However, they're not necessary for treating allergies in dogs. Ultimately, treatment will depend on the type of allergies your dog has. For example, if your dog has fleas, your vet may send you home with an effective flea control product or medication. Meanwhile, if your dog has food allergies, your vet will put them on an elimination diet to rule out potential allergens in their kibble or wet food causing the reaction. 

Here are a few ways the different allergies are treated:

• Flea allergy treatment: If your vet diagnoses your dog with flea allergies, they'll aim to eliminate the infestation while making your dog more comfortable by reducing the itching. There are several ways to treat fleas and prevent them from recurring, including topical and oral medications. Of course, since fleas live in the environment, your vet will send you home with instructions on how to remove them from your home, which may include thoroughly cleaning and vacuuming.² 
• Food allergies treatment: Dogs with food allergies are typically more difficult to treat because your vet can't determine which ingredients they're allergic to. As we've mentioned, dog food allergy tests are available, but they're not considered accurate. Instead, your vet will put your dog on an elimination or hypoallergenic diet to determine if they have a food allergy.² Other options include treating the symptoms with medication or steroids to control the itching. 
• Environmental allergies treatment: Unfortunately, environmental allergies are often the most difficult to treat because you won't be able to completely eliminate things like dust and pollen from your dog's environment. Instead, vets will treat your pet with oral medications, injectables, or steroids to reduce their symptoms. Immunotherapy may also be an effective treatment method for environmental or seasonal allergies. With immunotherapy, dogs receive an injection to make the immune system less reactive to allergens.²

FAQs

How can I test my dogs for allergies?

You can test your dog for allergies by taking them to the vet to discuss their symptoms with a professional. Since allergy symptoms closely resemble symptoms of other illnesses and diseases, your vet will want to rule those out before beginning allergy testing. From there, your vet will use either intradermal or blood testing to determine what your dog is allergic to. 

Home allergy tests also use saliva or a hair sample to determine what your dog is allergic to. However, these tests are not considered reliable and shouldn't be used to diagnose your dog with allergies because they can be inaccurate. 

Unfortunately, allergy testing is only available for some types of allergies. For example, dog food allergy tests are not considered accurate and can result in false positive results. If you're worried about your dog's allergies, the best thing you can do for them is have them diagnosed and treated by a vet. 

What is the most accurate allergy test for dogs?

The most accurate allergy test for dogs is the intradermal test, which consists of putting your dog under anesthesia before a vet injects them with various allergens and waits for an immune response in the form of swelling or a hive. This type of allergy test works the same for dogs as for humans. However, because it requires anesthesia, most pet parents will choose RAST testing instead. RAST tests use a blood sample, and they're less accurate than intradermal testing but can help vets and pet parents determine the best treatment. 

Can vets do anything for dog allergies?

Yes, vets can treat allergies in a few different ways. The type of treatment they use depends on the type of allergies your dog has. For example, if they believe your dog is allergic to their food, they may suggest a hypoallergenic or elimination diet. Meanwhile, if your dog has environmental allergies, they'll likely prescribe allergy medication to reduce their symptoms and make them more comfortable. 

Final Notes

Dog allergy testing isn't used to diagnose allergies in dogs. Instead, it's used to determine which potential allergens are causing your dog's reaction. Unfortunately, these tests are only worthwhile if you pursue treatments targeting specific allergens. Otherwise, your vet will likely diagnose your pet's allergies using various methods, including ruling out underlying health issues that can cause similar symptoms and treating them with medication or topicals to reduce the unpleasant symptoms. 

Meet with a licensed vet online to discuss your pet's allergies and find the best treatment options. Dutch vets can recommend therapies and medications to reduce your dog's symptoms and prevent secondary infections from scratching and excessive grooming due to your dog's itching.