Allergies are one of the top reported health concerns for pet owners, affecting about 20% of dogs. Because allergy symptoms vary widely, it can be difficult to pinpoint the cause of a dog’s allergic reaction. Now, Embark offers a new genetic result that tells pet owners about their dog’s genetic risk for allergies as a score between 0 and 100%.
Learn more about the science behind the new allergy risk scores, plus how to use this information in your dog’s care.
Why do dogs get allergies?
Allergies are caused by a combination of genetics and the environment. They require exposure to an allergen—a substance that triggers the immune system to ramp up an allergic response. While we know about the cellular processes that produce allergic reactions in dogs, scientists continue to study how genetic variation controls those reactions.
DNA plays an important role. Allergies are highly heritable, which means that if a dog’s ancestors had allergies, that dog is also usually at higher risk for allergies themselves. Any dog can develop an allergy, but some breeds are more likely to be affected.
This bar chart shows the percentage of purebred dogs of the 20 most common breeds in Embark’s customer base that are reported by their owners as having environmental allergies (atopy). Only dogs that were at least three years old were used to calculate prevalence.
While a dog’s DNA can influence their risk of allergies, whether or not they actually develop allergies ultimately depends on what allergens they are exposed to in their daily life. For example, if a dog is predisposed to flea allergies, but takes preventive flea medication and is never bitten by fleas, they won’t show any flea allergy symptoms.
Does Embark test for allergies?
Embark now offers a first-of-its-kind genetic risk result for allergies, available as an upgrade to Breed ID or Breed + Health Tests. The results are called allergy risk scores. Customers can upgrade their results anytime to see their dog’s allergy risk scores.
Customers who upgrade will receive four unique risk scores showing their dog’s risk of developing four different types of allergies:
- Environmental allergies (also called atopy)
- Food allergies
- Contact allergies
- Flea allergies
How do allergy risk scores work?
Our models take into account hundreds of genetic variants, plus breed ancestry, to calculate your dog’s unique allergy risk scores. Together, these genetic variants explain 50–80% of a dog’s allergy risk.
Embark allergy risk scores use a dog’s DNA to estimate their likelihood of developing four different types of allergies on a scale of 0% to 100%. For example, if a dog’s risk score for food allergies is 20%, that means they have a one in five chance of developing food allergies.
Embark allergy risk results show your dog’s absolute risk (their chance of developing an allergy) and their relative risk (how their risk compares to the average dog). In this example, Daisy’s absolute risk for food allergies is 19.3%, which means she has a 19.3% chance of developing a food allergy over her lifetime. Her relative risk is 1.7 times that of the average dog.
How did Embark develop the allergy risk scores?
Embark calculates a dog’s allergy risk scores using proprietary statistical models developed by our scientists. To create these models, we first gathered genetic data and owner-reported allergy diagnoses (i.e., whether or not a dog has a particular allergy) from hundreds of thousands of dogs. We used the data to perform a genetic association study. This study identified genetic markers in the dog genome where dogs’ genotypes strongly correlate with their allergy diagnoses.
Next, we used machine learning to fit models that estimate dogs’ likelihood of developing allergies based on their genotypes at the most important genetic markers, their chromosomal sex, and their genetic diversity.
In the process of developing these models, we found that some genetic variants have different effects on allergy risk in different breeds. That’s normal for complex diseases like allergies, which arise from a combination of genetic and non-genetic factors.
To account for these differences by breed, and to make sure we are reporting the most accurate results possible for all dogs, we trained separate models for certain groups of closely related breeds and identified the best models for each breed. All of these quality control steps are baked into your dog’s results before you receive them. Your dog will only receive test results from models that best correspond to their individual ancestry, whether they are purebred or mixed breed.
How accurate at Embark’s allergy risk scores?
Our allergy risk score models perform comparably to similar risk models from human consumer genetic testing companies. They were developed using data from hundreds of thousands of genetically diverse dogs, so we’re confident that our models are best in class.
We evaluated the performance of our models by testing them using independent sets of dogs that were not part of the model design process. That evaluation gave us unbiased estimates of the accuracy of our models. All models showed a high degree of concordance between predicted and observed allergy prevalence. We may continue to refine these models over time as we collect more data.
The above graph shows the correlation between true (observed) environmental allergy prevalence and prevalence predicted by our allergy risk score models in our validation dataset. The predicted allergy prevalence is highly correlated to the reported allergy prevalence, demonstrating the accuracy of our allergy risk score models.
It’s important to remember that our allergy risk scores look only at the genetic factors affecting a dog’s risk for allergies. They can’t tell us about a dog’s environment.
Our allergy risk scores do not diagnose allergies and do not determine which specific allergens your dog may be allergic to. Your dog’s Embark results cannot be used to create “allergy shots” (where a small amount of substance a pet is allergic to is administered to them on purpose to allow the immune system to get used to it).
How can I use these allergy risk scores in my dog’s care?
Many medical conditions—and even different types of allergies—often show similar symptoms, making it difficult to identify the cause. That’s why we provide your dog’s risks for four allergy types, ranked from highest to lowest, so you and your vet can narrow down the cause of their symptoms and prioritize treatments that are most likely to help them recover. You can send results directly to your veterinarian from your dog’s Embark profile.
A genetic test is not a diagnosis, but knowing your dog’s genetic risk of developing allergies can help you know what signs to look for, how to prevent allergic reactions, and how to help your dog feel better if a reaction occurs.
Even if you know your dog’s family history of allergies, our risk scores provide finer resolution than pedigree-based risk estimates, because they consider each dog’s specific genetic profile rather than relying on predicted coefficients of relatedness, which are based on population averages.
Find out your dog’s allergy risk
Allergy risk scores are available as an upgrade to the Breed + Health Test and Breed ID Test. Simply log in to your dog’s Embark profile to get started.
Embark Breed + Health Test
$199
Embark Breed ID Test
$129
Learn more about the signs of allergies in dogs, common triggers of food allergies, and what to do if your dog has contact allergies.
Andrea Slavney, PhD
Read more about Andrea Slavney, PhD
