“Up to 30% of people who are allergic to dogs are actually allergic to one specific protein that’s made in the prostate of a dog,” said Dr. Lakiea Wright, an allergist at Brigham and Women’s Hospital in Boston.

While the protein was identified years ago, reliable lab tests for the allergen that were approved by the US Food and Drug Administration were only developed in the last few years.

“If you’re allergic to only that specific protein in the male dog, you may be able to tolerate a female or a neutered dog,” Wright said.