Scientists at Kindred Companion Sciences used CRISPR-Cas9 to breed the first genetically engineered beagles, named Alfie and Bailey, born in September 2024. The pups lack the primary protein responsible for human dog allergies, offering a potential proof-of-concept for creating hypoallergenic pets without compromising animal health.
For millions of people worldwide, sharing a home with a dog comes with a persistent cost: sneezing, itchy eyes, and congested airways. Dog allergies are estimated to affect about 15 percent of the human population, often triggered when the immune system mistakes harmless proteins for dangerous pathogens and mounts a full-blown defense. Until now, people sensitive to canines have had few options beyond limited allergen immunotherapy or choosing low-shedding breeds like poodles and goldendoodles. Those alternatives fall short because even non-shedding dogs still produce allergy-causing proteins in their saliva, hair, and dander.
Researchers have tried to bypass this biological hurdle before, mostly by attempting to clone pets, but those older efforts often resulted in sicker puppies with excessive genetic similarity. Two years ago, scientists used CRISPR to reduce allergy-causing proteins in a cat named Alsik, though the safety of that technique for other felines remains uncertain. Now, Kindred Companion Sciences has taken a different route entirely.
How Scientists Edited the Beagle Genome Using CRISPR
The breakthrough centers on a single target: a protein known as canis familiaris allergen 1, or Can f 1. Can f 1 is found in the animals’ saliva and dander, attaching to dust and hair in the home environment.
They edited the genetic code inside dog skin cells, switching off the primary gene responsible for manufacturing the allergen. Researchers then transferred the modified genetic code into eggs and implanted them into a beagle surrogate mother.
The resulting litter included two healthy female pups, Alfie and Bailey, born in September 2024. Laboratory testing of their saliva and fur confirmed that the allergy-causing protein was entirely absent. The research detailing the project was published in The CRISPR Journal.
Both dogs have received regular veterinary examinations and exhibited no clinically apparent health abnormalities to date. The dogs also display normal mentation and age-appropriate activity, with no clinically apparent behavioral abnormalities. Researchers, The CRISPR Journal
As they approach their second birthday, Alfie and Bailey weigh approximately 9 to 10 kilograms, or 20 to 22 pounds, a growth trajectory that aligns with female beagles. Bailey now lives in New York with Matt Walker, a study author, while Alfie lives in Florida with another scientist from the company.
Testing the Hypoallergenic Beagles on Human Allergies
To determine whether the genetic alteration actually stops allergic reactions, researchers tested human subjects against extracts from the modified beagles. Walker, who has lived with pet allergies for his entire life, participated in direct skin-prick tests.
When exposed to extracts from traditional breeds like poodles and goldendoodles, Walker’s skin produced an inflammatory response. But extracts drawn from Alfie and Bailey’s saliva and dander produced no reaction whatsoever. Breeds marketed as hypoallergenic still produce allergy-causing proteins, making the specific removal of Can f 1 a significant departure from standard breeding practices.
For Walker, the scientific milestone carries profound personal meaning. Growing up, his allergies kept him away from dogs entirely, and even family dogs marketed as hypoallergenic triggered painful rashes and itchy eyes.
Study author Matt Walker stated that as someone living with dog allergies, this work is deeply personal, explaining that for most of his life he assumed he would never have a dog, yet he has lived with Bailey for almost two years and described her as a happy, healthy, and incredibly sweet dog who reminds him every day why this work matters.
Broader Implications and Open Questions for Future Breeding
While the initial results show promise, independent experts urge caution before assuming the technique solves pet allergies for everyone. Can f 1 is the primary culprit tested in the study, but it is not the only protein responsible for canine allergies.
Dr. Jeff SoRelle, a pathologist at the University of Texas Southwestern Medical Center who was not involved in the research, noted that future research must test the dogs on a broader swath of the human population to verify real-world effectiveness.
Furthermore, outside observers have pointed out ethical questions surrounding the commercialization of gene-edited pets, including potential impacts on animal shelter adoption rates. The researchers emphasize that the specific genetic edit performed on Bailey and Alfie is a rare variation that does occur naturally in some dogs, suggesting it should not introduce unforeseen developmental disorders. The team plans to continue monitoring the animals during routine veterinary visits and intends to expand testing to service animals and other breeds before considering any commercial application.
