Guide to Testing for Allergies in Dogs:
How to Know Whether Your Dog is Allergic to Something

For any dog allergy testing, make sure that your dog is not taking any antihistamines or corticosteroids (at least 2 weeks before the testing), or it can affect the quality of the testing results.

In the meantime, take a look at some tips to ease the symptoms and help your dog:

Once you are positive your dog has allergy symptoms, perform an allergy test, and gather all the information, it's recommended to schedule a veterinary appointment.

In some cases, the allergic reaction can be eliminated by limiting the exposure to the allergen.

But some allergies in dogs, especially skin infections, may require medication.

A specialist may prescribe corticosteroids or antihistamines for dogs, especially in the case of atopic dermatitis and similar skin allergic reactions. In severe cases, an intradermal injection may be needed.

Consequently, your dog can also develop an allergic reaction to the injection. Symptoms vary and they can be grouped into those that:
Require immediate intervention:

• hives
• vomiting
• collapse

Should be reported:

• listlessness
• excess panting
• frequent swallowing

For milder conditions, just make a brand-new diet plan, with some wholesome ingredients, excluding the things your dog is allergic to.

Types of Dog Allergy Tests

1. Strand Hair Test (My Recommendation)

Out of all types of allergy testing for dogs, this allergy test provides the most extensive and reliable sample report.

Here’s how it is performed:

1. You receive your allergy test kit (currently, there’s no better than the 5Strands one). You’ll have to fill out some info regarding your dog and your address.
2. Collect the hair. 10-15 strands should be enough (preferably, pulled out or clipped - not shed).
3. Send the whole kit with the sample via mail. You will be provided with a pre-addressed envelope.
4. Wait. You will receive a notification email that the test has been delivered to their laboratory, and you should wait for around 5 to 7 days.
5. Analyze the report. Upon the arrival of the allergy testing result (again, via email), you can observe what your dog is allergic to. It’s pretty easy to follow (signaled in green, yellow, and red - according to severity).
6. Improve your dog’s life! 🙂 Now that you know what’s causing allergies, it’s time to stop that scratching & itching forever, and reevaluate your dog's diet - perhaps go with homemade food so that you can control what your dog takes in?

2. Saliva Testing

Although I suggest strand testing, saliva tests can also be a good approach for dogs - certainly better than blood and intradermal skin allergy tests.

The procedure is quite similar to the hair allergy test, so I won’t describe saliva allergy testing in detail. You’ll receive the allergy testing kit, fill in the info, and mail it back in the pre-addressed envelope.

What differs is that you should put the cotton device in your dog’s mouth and collect the saliva sample until the swab indicates that it is enough.

3. Veterinarian (Blood Allergy Testing/Intradermal Skin Testing)

At home dog allergy test for dogs type of products are much more convenient than veterinary blood allergy testing and intradermal skin testing.

It is reasonably easy to perform at-home allergy tests, and they show the same results as blood and skin test.

Not to mention that blood and intradermal skin testing is almost three times as expensive as the homemade alternative!

You should opt for a veterinary skin or blood test instead of a home-based one only if you don’t find the ingredient you’re suspicious of on the list of allergens. But that’s very unlikely, especially with the gold standard, 5Strands Test, that contains more than 350.

Veterinary Blood Tests

Veterinarian blood tests include blood samples, and - just like us, humans - our dogs are not too fond of blood extraction. No need to submit your dog to torture!

Veterinary Intradermal Skin Tests

Intradermal skin allergy testing is very unpleasant for dogs. If you've ever had one, you'll know what I'm talking about - it involves the injection of allergens under the surface, and the same goes for dogs.

Administering Injections

Since the success of blood and intradermal skins tests are considered to be controversial by many dermatologists, professionals recommend administering injections. The dosing protocol can be selected by the owner and he will be giving injections to the pet. Initially, your dog will receive increasing amounts of PNU - protein nitrogen units.

How Do Dog Allergy Tests Work?

There are two main and most accurate types of dog allergy testing - blood testing and intradermal skin testing. Both types of allergy testing are administered differently, and it has different pros and cons.

The best time to perform these tests is during the allergy seasons when the allergens are high and cause severe allergic reactions; therefore, you will most likely generate an accurate result during this period.

The main rule is that testing should always come after examination for other potential causes and irritators like fleas, mites, bacterial and yeast infections, and hypothyroidism. 

Also, the chances are high that your vet will recommend a two-week hypoallergenic diet to rule out a possible food allergy. It is very hard to determine a food even when using a test, so the best way is to combine test and h dietary manipulation. Once potential irritations and food allergy possibilities are ruled out, the vet will order a blood or skin test to determine the exact allergen's presence.

Blood allergy testing - how it's done?

Blood allergy testing is the most common form of testing since it is convenient and easy to do. 

This test is performed by taking a blood sample from a patient and submitting the sample to a laboratory for further analysis. The lab then tests the blood, looking for allergen-specific antibodies (IgE) for a number of allergens that are expected to contribute to the allergy, including:

• Pollen
• Mold
• Dust
• Food allergens
• Allergic reactions on materials

Each lab uses different techniques to perform the test, and these techniques may vary in accuracy and clinical relevance, of course. 

As said, blood allergy tests can also determine food allergies and allergic reactions to materials like cotton or nylon, but this test is less reliable than skin allergy testing.

Pros and cons

Blood allergy testing is convenient, and it can easily be performed in general practice. Also, patients do not have to be sedated or shaved, which is great since this might be stressful for dogs. All that is needed for this procedure is a single blood sample.

However, there are drawbacks to blood allergy testing. 

These tests are very often associated with false positives that cannot be confirmed through intradermal skin testing. Positive allergy test results have also been observed with no evidence of atopic dermatitis, and usually, allergen-specific IgE does not correlate with the real clinical picture and severity of the allergic reaction

These findings put a shade on the validity of blood allergy testing. However, the patients treated on the basis of blood allergy testing often report clinical improvement, so blood testing can't be ruled out as a bad decision, but skin testing will always be more accurate.

Skin allergy testing - how it's done?

Skin allergy testing is more invasive since it requires sedation due to the length of time the patient needs to be still. Intradermal skin allergy testing involves injecting small quantities of allergens just under the dog's skin. Approximately 40 to 60 injections are given in a single area of the body, usually the abdomen.

A "positive" response to a specific allergen appears as a swelling at the injection site and is observed within 20 minutes of injection. If the swelling does not occur, it is assumed that the dog is not allergic to that specific allergen.

By examining the visible skin reactions, a dermatologist can determine which allergens are triggering your dog's allergic reactions.

Steps when performing skin allergy testing for dogs:

• The dog is sedated and monitored during the whole procedure
• The dog is placed to lay on its side
• A small area on the dog's side is shaved
• Small needles inject tiny amounts of test allergen just under the skin in a specific pattern and order 
• After a few hours, the shaved area is examined to determine which allergens caused the reaction. 

Skin allergy testing has been accurate in 75% of cases of determining the presence of dog allergies. But skin allergy tests can be inaccurate if patients have received antihistamines or steroids over the course of months before testing.

Pros and cons

When some other allergy tests are evaluated, they are usually compared to intradermal testing, which is considered a gold standard in allergy testings.

There are some cautions and restrictions for dogs that are about to receive intradermal skin allergy testing:

• Female dogs should not be tested if they are pregnant or in heat (hormones impacts testing)
• A test should be performed at the end of the allergy season 
• No baths should be given at least five days before testing
• Dogs must fast the morning of the procedure 

This test cannot be performed if the dog has received the following medications:

• Long-acting injectable steroids within 90 days prior to testing
• Oral steroids within 30 days prior to testing
• Topical steroids 14 days prior to testing
• Antihistamines 7 days prior to testing
• Essential fatty acids 7 days prior to testing

This can be challenging for some dogs who suffer from severe pruritus when medications are discontinued.

Also, a need for sedation or anaesthesia is a problem for many owners. A small disadvantage is that all hair must be clipped from the test site, which may present a significant disadvantage for show dogs. 

Finally, intradermal allergy testing requires an experienced dermatologist to administer the test and interpret the results, which can present a significant obstacle for clients in rural areas.

However, these types of tests are always performed by the vet, if you want to do a quick allergy check up at home on your own, you can always acquire home allergy test kits.