My Westie is allergic to chicken. Can she still eat egg, or will it cause the same reaction?
This is a common question with an unclear answer, and there is limited research on this in dogs. As in many cases, we can look at research in the human field (see references below) to pinpoint the allergens in chicken and eggs. From here, we can determine whether or not a dog is likely to be allergic or intolerant to both proteins or just one.

What is the difference between egg and chicken allergies?
As we know, top notch protein is fundamental to a species-appropriate diet. If you have a dog with allergies or intolerances, finding a good quality protein source that won’t trigger a reaction can be tricky. In cases such as these, feeding novel proteins is recommended – in other words, a protein source that your dog hasn’t eaten before and therefore will not trigger the allergic response.
Enter eggs, a fantastic source of nutrition that can really complement your dog’s diet. Being a complete protein, eggs are an excellent novel protein pick, rich in essential amino and fatty acids, vitamins, and minerals. Surprisingly, however, they’re often overlooked, and owners opt for wilder or more exotic proteins.
Chicken is one of the most common allergens. Understandably, many associate eggs with chicken, assuming they will cause the same allergic response. But is there any truth in this? Let’s delve a little deeper…
If we look at egg whites, they contain four allergens known as d1, d2, d3 and d4. Egg yolk includes allergens d5 and d6. These are unique to eggs, whether they are duck, quail or indeed chicken. You can be allergic to one or all of the allergens in the yolk, the white, or both. The allergen most common in chicken meat is d5 and Gal d7. Note that d5 is found in both the egg and the chicken.
Your dog can be allergic to any one of the ‘d’ allergens numbered 1-7. Unfortunately, allergy tests don’t tend to get any more specific than stating if your canine is allergic to eggs or chicken – this leaves you unclear as to which specific allergen is causing the reaction. They are also costly, and retesting is often advised, taking more money out of your pocket. So, where do you go from here?

Feeding egg whites vs yolks
Splitting the egg and feeding the white and yolk separately isn’t the best way forward. The white contains protein enzyme inhibitors that, if fed uncooked in large quantities, can affect digestion. The whites also contain avidin, which stops the absorption of biotin, an essential B vitamin. Feeding the egg whole will counteract this as the yolk contains plenty of biotin (as does a well balanced diet), keeping things ticking along nicely.
Put simply, it’s wise to feed the egg in its entirety or not at all, so we’d recommend avoiding dog food that only contains one element.
So, can my dog eat egg?
Assuming dogs react to the same allergens as people, we can conclude that your pooch may be allergic or intolerant to chicken, egg, or both.
To identify the root of the reaction, I’d suggest a little trial and error. For example, over at least four weeks, feed an egg twice a week and feed no chicken at all, watching for signs of an allergic response – symptoms of a canine food intolerance may present as digestive issues or itching.
This exercise is well worth doing. As I mentioned earlier, eggs are packed with health-boosting nutrients, making them an asset to any diet, be it raw, cooked, or cold pressed. It would be a shame to write them off, especially if your dog is on a veggie diet! That being said, there are plenty of other wonderful whole foods you can feed that don’t carry the risk of an allergic flare-up.

When dealing with allergies, we need to look at the bigger picture. Feeding novel food items will help in the short term, but your pet can soon become allergic to the new food. This is why it’s recommended that you slowly increase the variety of proteins you feed and regularly rotate to prevent an intolerance from developing.
A weak microbiome is often the cause of allergic reactions and intolerances. Building one that is robust is a great first step towards combatting allergies in the long-term and cultivating a healthy digestive system – around 70% of a dog’s immune system resides there. In addition to ensuring your canine’s on a species-appropriate food plan, you can lay the groundwork for a thriving microbiome by adding foods to her diet that promote a soothed, happy digestive system, such as herbal blends.
I hope this helps.
Katie x
References