Gene-edited beagles produce no detectable major dog allergen in early study

Scientists have created two beagle puppies that produce no detectable Can f 1, the protein responsible for the majority of human dog allergies. The study, published in The CRISPR Journal, used CRISPR-Cas9 to insert a single DNA building block into the Can f 1 gene in dog skin cells, scrambling the genetic instructions and switching off production of the allergen.

The edited cells were used to create cloned embryos via somatic cell nuclear transfer. Twenty-five embryos were transferred to a surrogate mother, resulting in the birth of two female puppies named Alfie and Bailey. Whole-genome and targeted sequencing found no unintended genetic damage from the editing process.

Biochemical tests on saliva, hair and dander from the gene-edited beagles detected no Can f 1 protein. For comparison, the protein was readily found in samples from a normal beagle, a standard poodle and a goldendoodle, including breeds often marketed as hypoallergenic.

In a skin-prick test with one human volunteer, extracts from the normal beagle, poodle and goldendoodle all produced allergic wheals. Extracts from the two gene-edited beagles triggered no reaction. The volunteer's response to the edited dogs was described as striking by the research team.

About 15% of the global population lives with dog allergy, which can increase the risk of hay fever and asthma. Current management relies on avoidance, cleaning or immunotherapy that targets the human immune system rather than the allergen source.

The researchers emphasized that this was a proof-of-concept study. Long-term health effects on the dogs remain unknown, and the puppies were kept under strict veterinary observation. Commercial application would require establishing long-term safety, ensuring animal welfare oversight and meeting regulatory requirements.

The work demonstrates that it is technically feasible to eliminate a major allergen at its biological source in a living animal. Further studies will be needed to assess whether the genetic change affects the dogs' health or whether other minor allergens become clinically significant.