World’s First Gene-Edited Horses Stir Debate in Polo

The world’s first gene-edited horses are causing a stir in polo — a sport long celebrated for tradition and pedigree.

In Argentina, widely regarded as the global capital of polo, breeders and players have embraced cloning and other reproductive innovations. But CRISPR, the gene-editing tool, is proving to be far more controversial.

In Buenos Aires Province, five ten-month-old foals graze contentedly on alfalfa in a fenced pasture. With honey-brown coats and white markings on their faces, they look like any other horses. Yet they are not. These are the world’s first genetically edited horses — clones of Polo Pureza (Polo Purity), a prize-winning stallion, with a single CRISPR-designed DNA sequence introduced to boost explosive speed.

The company behind them, Argentina’s Kheiron Biotech, says gene-editing has the potential to transform horse breeding. Unlike cloning, which produces a genetically identical copy, CRISPR works like molecular scissors, cutting and fine-tuning DNA. Kheiron used the technique to suppress the myostatin gene, which normally limits muscle growth, aiming to create stronger muscle fibers for greater power and speed.

But polo is not ready to accept them just yet.

While Argentina has welcomed technologies like cloning to refine breeding, its polo governing bodies are pushing back against genetically engineered (GE) horses. The Argentine Polo Association has already banned them from competition.

“I don’t want them in polo,” said Association President Benjamín Araya. “It takes away the magic of breeding. I enjoy choosing a mare and a stallion, breeding them, and hoping for something extraordinary.”

Similarly, the Argentine Polo Horse Breeders Association told Reuters it will monitor the foals for four to five years before deciding whether to register them as official Argentine Polo Ponies.

Still, Kheiron remains confident the sport will come around. “I’m really not that worried,” said Gabriel Vichera, the company’s scientific director. “We just need to keep educating people.”

Unclear enforcement

It remains uncertain how the ban would even be enforced. Argentine regulations make no distinction between cloned, gene-edited, or traditionally bred horses — and neither does the Polo Association.

Some breeders admit cloning helps preserve bloodlines, but insist gene-editing goes too far and threatens the business.

“This destroys breeders,” said former professional player Marcos Heguy. “It’s like using AI to paint. The artist’s role disappears.”

Eduardo Ramos, who began breeding in the 1970s, countered that skepticism of biotech is nothing new. “People doubted embryo transfers and cloning, too,” he said. “But science and technology will keep moving forward. Those who say it shouldn’t happen won’t be able to stop it.”

Polo’s long legacy

Polo originated in Central Asia before being brought to Argentina by British settlers, who founded Buenos Aires’ first polo club in 1882. Often compared to hockey on horseback, the sport is costly — top players may rotate through a dozen horses in a single match. In Argentina, it has long been dominated by wealthy landowning families.

Government data shows the country exported around 2,400 polo horses last year, and Argentine ponies remain a dominant force in elite competitions such as England’s Queen’s Cup and the Argentine Open. Surrogates are already widely used to carry embryos, and unlike horse racing, polo allows clones.

The first cloned horse was born in 2003. Legendary player Adolfo Cambiaso helped popularize polo clones after a clone of his prized stallion Cuartetera sold at auction in 2010 for $800,000 — a moment that first captured Vichera’s imagination while he was a PhD student in biotechnology.

The following year, he co-founded Kheiron with businessman Daniel Sammartino. Their first cloned foal was born in 2013. Selling clones wasn’t easy at first; to gain traction, they offered free services to leading breeders in exchange for keeping some of the offspring. Today, the company expects to produce 400 clones by year’s end, accounting for more than half of all clones born in Argentina in 2025, according to breeders’ association estimates. Clones now sell for an average of $40,000.

In 2017, Kheiron took the next step, using CRISPR to edit embryos for nine GE foals, intended for research. The move sparked backlash among polo elites, some of whom approached Argentina’s biotech regulator to express concern about gene-edited horses entering the sport.