Scientist uses gene-editing to breed a dog that won't trigger his allergies - as experts say the technique 'opens the door to a lot more people being able to own pets'

A scientist has used gene–editing to breed a beagle that won't leave him sniffling, in a major breakthrough for people with pet allergies.Dr Matt Walker is a New York–based geneticist and lifelong dog lover whose allergies prevented him from ever keeping a pet of his own.But now, Dr Walker can comfortably cuddle on the sofa with his new puppy, Bailey, thanks to a small genetic tweak.While his allergies didn't go away, Bailey's saliva and hair no longer contain the key allergy–causing protein.Unfortunately, it will still be years before the millions of allergy–suffering animal lovers are able to get their own hypoallergenic beagle.Scientists will need to carefully monitor Bailey and her twin brother Alfie to make sure the genetic changes don't have any unintended health effects.However, Dr Walker's company, Kindred Companion Sciences, hopes that it will be able to repeat the trick with other breeds, to make an entire line of allergy–free pups available in the future.Professor Arthur Caplan, a bioethicist from New York University's Grossman School of Medicine, says: 'It opens the door to a lot more people being able to own pets.' Scientists Matt Walker has used genetic editing to make a puppy that won't set off his allergies. Pictured: Matt Walker and his wife Maggie pose with their beagle, Bailey Although low–shedding dogs like Poodles and Cockerpoos are often sold as 'hypoallergenic', these dogs still produce the same allergy–triggering proteins as any other breed.In the past, scientists have attempted to make truly allergy–free pets using cloning.However, those puppies ended up being unhealthy and were too genetically similar to breed into a new population.To avoid those issues, Dr Walker created Bailey and Alfie using the Nobel Prize–winning technique called CRISPR gene editing.CRISPR is a tool that allows scientists to make edits in living DNA, cutting out unwanted mutations or inserting new sections of DNA at key points.Making the allergy–free puppies began in the lab, where scientists took dog DNA and used CRISPR to deactivate one of the genes responsible for making allergy–causing proteins.They then took that edited DNA and inserted it into eggs, which were then implanted into a surrogate beagle mother.In 2024, that mother gave birth to two puppies, neither of which had the allergy–causing genes. Dr Walker says that a small change to Bailey's genes allows him to cuddle on the sofa without sneezing or sniffling Bailey and her twin Alfie were created using a technique called CRISPR, which allowed scientists to deactivate the gene that produced allergy–causing proteins in their saliva What is Crispr–Cas9? Crispr–Cas9 is a tool for making precise edits in DNA, discovered in bacteria.The acronym stands for 'Clustered Regularly Inter–Spaced Palindromic Repeats'.The technique involves a DNA cutting enzyme and a small tag which tells the enzyme where to cut.By editing this tag, scientists are able to target the enzyme to specific regions of DNA and make precise cuts, wherever they like.It has been used to 'silence' genes – effectively switching them off.When cellular machinery repairs the DNA break, it removes a small snip of DNA.In this way, researchers can precisely turn off specific genes in the genome. Kindred Companion Sciences tested their hair and saliva, and found that it was completely free of the key allergy protein.Dr Walker was also put through an allergy prick test, piercing his skin with tiny needles loaded with samples from Alfie, Bailey, and normal dogs.His skin reacted to samples from a Poodle and Goldendoodle, but not from the beagles.'The feeling right now is sort of a mix of relief and awe and gratitude that it worked,' says Dr Walker.'It feels just amazing to get to have a dog.'Since this mutation can occur naturally in some dogs, the scientists are confident that it shouldn't trigger any unknown health complications.But it will still be important to monitor them at routine vet visits and make sure they stay healthy.Dr Walker has already had Bailey for a little over a year and says she's become a member of the family. Bailey's health will need to be carefully monitored to check that the genetic change doesn't have any unintended health consequences Experts say that the birth of Alfie and Bailey 'opens the door to a lot more people being able to own pets' In fact, experts are more concerned that Dr Walker's allergy–free dogs might actually be too much of a success, putting a dampner on efforts to rescue and adopt unmodified pups.Professor Caplan says: 'On the negative side, it may discourage people from trying to use strays and unwanted animals that are not engineered to be allergy–free.'Likewise, scientists say that more studies will be needed to ensure that these allergy–free gene edits are effective for everyone.Dr Jeff SoRelle, a pathologist at the University of Texas Southwestern Medical Centre, says that future research should test the gene–edited hypoallergenic dogs on more people with pet allergies.The gene that was switched off in Bailey and Alfie is the main allergy–causing gene, but it isn't the only one.Dr SoRelle says: 'We don't exactly know just how effective or broadly useful this could be for stopping dog allergy in humans.'That means many more rounds of tests will be needed before customers can purchase a pup certain to stop their sneezing.DOGS WERE FIRST DOMESTICATED SOME 20,000-40,000 YEARS AGOA genetic analysis of the world's oldest known dog remains revealed that dogs were domesticated in a single event by humans living in Eurasia, around 20,000 to 40,000 years ago.Dr Krishna Veeramah, an assistant professor in evolution at Stony Brook University, told the Daily Mail: 'The process of dog domestication would have been a very complex process, involving a number of generations where signature dog traits evolved gradually.'The current hypothesis is that the domestication of dogs likely arose passively, with a population of wolves somewhere in the world living on the outskirts of hunter-gatherer camps feeding off refuse created by the humans.'Those wolves that were tamer and less aggressive would have been more successful at this, and while the humans did not initially gain any kind of benefit from this process, over time they would have developed some kind of symbiotic [mutually beneficial] relationship with these animals, eventually evolving into the dogs we see today.'