Dogs and Humans Sometimes Share the Same Allergies

Are you and your pupper close enough to share allergies?

By Jennifer Grant

Image: Shutterstock

I remember it started as a small itch near my ankle bone, this little, raised patch of skin. I must have worked on it all night because in the morning, it was angry and inflamed and bleeding. Still itchy. Maybe a little bit bigger.


Then I tuned into this relentless jingle-jangle of dog tags as my sweet Homer (pre-Simpsons days. We called him Homer because he was, in fact, quite homely, but also because he had found his forever home). He was clawing at the back of his ear to the point that I had to walk over and stop him before he did some serious damage. I looked at what was bothering him…a small patch of raised (and now bloody) skin. Hmmmm…

Dog on a Bed itching ear

Image: Zivica Kerkez

What is this? Did Homer and I trduge into some sort of hidden patch of Poison Ivy? I darted to the backyard, silently chanting, “Leaves of three, let them be.” There were no leaves of three. Whew. Fast forward about 4.75 hours and I have visited the human clinic and the vet. Diagnosis? Eczema. A little OTC hydrocortisone and we both had a good night sleep.

How is this even possible? That my dog and I could have the same immune response at the same time?


Dog human allergies


Image: Elnur

The short answer is that dogs share 95% of their DNA with humans and 100% of our environment and lifestyle. All of the fuzz, spores, bacteria, hair, and other unmentionables are floating around both of your heads. It only takes one of these to trigger an immune reaction (aka allergy).

Lifestyle and diet also create a unique body microbiota that is actually extremely similar amongst all of the animals (be them human or canine) living in your house.  All of these little beings (parasites, bacteria, fungus, yeast) living in harmony until some external pressure, perhaps stress, perhaps too much sugar, creates an imbalance.

Researchers think the top contributing factor is environment.

Woman with itchy rash

Image: Albina Glisic

Emma Hakanen is the lead researcher for an allergy study conducted at the University of Helsinki in Finland. She and her team collected data from 5,722 dogs (258 different breeds) that ranged in age from three months to eighteen years old. The goal was to determine if city dogs and their country cousins differed in terms of allergy response, and how that compared with their humans.


The results showed that dogs living in urban settings had more frequent skin and food allergies, the dogs that were encouraged to engage in more outdoor play were less prone to allergies. And most interestingly, allergy symptoms in dogs and their humans appeared at the same time, be that sneezing, running eyes, coughing, or skin outbreaks.

dog and girl in bed

Image: Blackbourne

The “why” is a little less clear. It is hypothesized that the dog and human pairs that are frequently outdoors get exposed to toxins and bacteria that cause continual little immune responses, thereby priming the immune system (similar concept to a vaccination). The end result is a stronger immune system that responds appropriately to stimuli.

Image: Kira Yan

If you want to reduce your allergy response, and that of your dog, the simplest answer is to move to a more rural setting. This is not perhaps the easiest solution, so the next best thing is to spend more time outdoors. Go on, get outside now.