David Ishee is a Mississippi kennel operator with a passion for dogs and a plan to improve them using a gene-editing technology called CRISPR from a modest laboratory he’s built in a plywood shed.

Sound unlikely? It’s serious enough that the U.S. Food and Drug Administration, in a phone call last week, told Ishee he wouldn’t be able to sell any edited dogs without its approval.

Ishee, a member of what’s called the “biohacker” movement, says he is hoping to use inexpensive new gene-editing techniques to modify the genes of Dalmatians. By repairing a single DNA letter in their genomes, Ishee believes, he can rid them of an inherited disease, hyperuricemia, that's almost as closely associated with the breed as their white coats and black spots.

In early January, Ishee sent the agency a sketch of his plans to fix Dalmatians, expecting to be told no approval was needed. He didn’t immediately hear back—and soon found out why. On January 18, the agency released a sweeping new proposal to regulate cattle, pigs, dogs, and other animals modified with gene editing.

The federal health agency already regulates transgenic animals—those with DNA added from a different species. But what about a dog whose genome has been tweaked to repair a disease gene? Or to endow it with the gene for a trait, like fluffy fur, already found in another canine? According to the newly proposed regulations, such creations will also need federal approval before entering the marketplace.

That was a blow to breeders like Ishee, who think gene-editing technology can quickly help them make better, healthier animals, and reverse some of the damage done to specialized breeds. “I think it will be easier to teach dog breeders CRISPR than it will be to teach dog breeders why pure breeding is a bad thing,” he says.

Yet the potential ease of making modifications is raising questions about how CRISPR will be controlled. Last year, the U.S. director of national intelligence, James Clapper, ominously declared that genome editing was a potential “weapon of mass destruction.”

Ishee says he had a phone call with the FDA last week and didn’t get the impression the agency was enthusiastic to see people like him altering dogs. “I was hoping they would be there with me, trying to come up with creative solutions, to try to serve their needs and the animals’ needs,” he says. “But I didn’t get that feeling. They seemed pretty nervous, like I was out to get them.”

According to the agency’s new regulatory proposal, it plans to treat the edited portion of the animal’s genome as a veterinary drug. That means that just like a new pill, edited dogs can’t be sold, or even given away, without first proving they are safe and work as intended, a process likely to incur costly studies and piles of paperwork. For instance, it took the creators of GM “Aquabounty” salmon around 20 years to win approval to commercialize their faster-growing fish.

The new rules have larger companies concerned, too. Last December, a Minnesota biotechnology startup called Recombinetics fired off a letter to the FDA saying that it planned to start selling Holstein milk cows that it had genetically edited so that they wouldn’t develop horns. But now Recombinetics’s sizable investments are in doubt. Scott Fahrenkrug, the company’s founder, says he is ready to fight what he thinks are irrational rules.

“Trump isn’t letting those regs [get] enacted,” he wrote MIT Technology Review in an e-mail.

Ishee, based in the small town of Mendenhall, also wonders whether the regulations from Washington should be disobeyed. During a conference call webcast on YouTube last week, he and another biohacker mulled what would happen if they just started curing dogs anyway, in an act of civil disobedience.

“I feel like maybe the best thing is to just go ahead and produce the healthy animals and then just tell people,” says Ishee. “We cured this disease, but the FDA won’t let us.”

Humans have been shaping the DNA of dogs for millennia. But the breeding efforts that produced the Dalmatian’s spots, or the pug’s flat snout, have also led to serious health problems. Certain prized bulldogs can’t even give birth without human assistance. “Dogs have more genetic diseases than any other species on the planet,” says Ishee. “So that’s us. We did that.”

A problem for Dalmatians is that the breed lacks a working copy of a gene needed to clear uric acid, causing stones that can block the urethra and can lead to a burst bladder. After several centuries of inbreeding, few Dalmatian have a normal copy of the gene. Although you could introduce a healthy gene by mating a Dalmatian with another dog, then you’d dilute thefamous dog’s signature look. “Dog breeders are kind of obsessed with pure breeding,” says Ishee.

David Ishee

Ishee’s plan is to purchase or build DNA that has the correct gene, as well as the molecular ingredients needed to perform the CRISPR gene editing. He would then add it to Dalmatian sperm before artificially inseminating a female. Hopefully, the mutated DNA letter would be repaired in at least some of the resulting litter of dogs.

Whether Ishee can pull it off isn’t at all clear. In the past year, Ishee says, he’s tried to make “bioluminescent” mastiff puppies by adding DNA from glowing bacteria. Those experiments, intended as a test run for curing canine genetic diseases, have no so far been successful.

Samantha Nicole Lotti, an animal science researcher at the University of Illinois at Urbana-Champaign, says the sperm technique Ishee wants to use can be unpredictable and still hasn’t been paired with CRISPR to repair a gene, the kind of gene editing he needs to do. “This does not mean it is not possible,” she notes.

Just like researchers at large universities who modify animals for research, Ishee says, he was told the FDA will allow him to edit Dalmatians so long as he keeps the resulting puppies on his property, in a kind of quarantine, and doesn’t sell them or give them to other breeders.

Ishee isn’t sure he sees the point in fixing just a couple of dogs. He wants to spread the improvement far and wide. “Now that the technology exists, we have an ethical obligation to do something about the genetic problems we created,” he says. “It’s a horrible disease, they all have it, and nobody seems to be willing to fix it.”

Correction: March 8, 2017

An earlier version of this article misstated the number of dalmatians that have a genetic mutation that causes uric acid disorder. It is most dalmatians, not all. In 2011 the American Kennel Club voted to recognize certain dogs without the trait as purebred dalmatians.