World’s First Sex Selected Puppy Litter Born In America

Five cuddly puppies born in American are more than your average litter. They're the world's first dogs to have their sex selected prior to conception via cutting-edge cell-sorting technology developed by an American biotech company.

The black Labrador pups, three female and two male, join a long line of animal species the group. has demonstrated can be successfully artificially inseminated with sex-sorted sperm to achieve the desired outcome — female or male offspring. To date, XY(R) Sex Selection Technology has been used to produce hundreds of thousands of sex-selected offspring of various animal species. Cattle, horses and sheep have benefited from this technology, which also has been successful in elk, domestic cats, the bottle-nosed dolphin and the Mediterranean water buffalo.

"We are delighted to show our sex-selection technology also works in the canine world," said Dr. Mervyn Jacobson, president and CEO of XY Inc., an international biotechnology company based in Fort Collins, Colo.

XY Inc. holds worldwide licenses and patents to a technology that is revolutionizing animal breeding, particularly the dairy cattle industry in which literally millions of dairy cows are needed to satisfy the need for increased milk supply in developing countries.

The successful births were a collaborative effort among XY Inc.'s research team; Dr. Greg Burns, DVM, owner of South mesa Veterinary Hospital in Fort Collins; and, of course, Morgan's Chocolate Rose, the patient mom of the rambunctious brood. Rose is owned by Steve Huffman and his family. Huffman is a laboratory technician with XY Inc.

"Over the last several years, XY Inc. has been approached by organizations breeding seeing-eye dogs or dogs used by law-enforcement agencies and the military. These groups have an interest in breeding technology as a way to improve and expand their breeding pools of animals desired for certain traits or temperament," Jacobson continued.

In the case of seeing-eye dogs, Labradors, particularly females, are a desired breed due to their calm and gentle disposition and intelligence.

"Producing a single litter of five pups is only the beginning of the process to prove the sex ratio really can be controlled, but if the sperm-sorting process is proven to work with canine semen over many litters, this will be a major step forward," commented Eldin Leighton, The Jane H. Booker Director of Canine Genetics, The Seeing Eye, which breeds Seeing Eye(R) dogs.

While XY(R) Sex Selection Technology typically guarantees at least a 90-percent accuracy rate in selecting for the desired offspring in cattle and other animals in which the technology has been rigorously field-tested and used in breeding for many years, the Labrador litter of sex-selected puppies was 60 percent accurate in delivering the desired sex — female.


John Schenk, XY Inc. reproductive physiologist, explained the purity of the doses of sexed dog sperm was sacrificed to achieve the quantity of semen need for AI.

"We are reasonably certain the less-than-optimum purity of the X-sorted sperm doses, which was 81 percent, had significant bearing on the female/male split in the litter," said Schenk. "There was an 18-percent chance we would end up with this combination in a litter of five."

A typical dog ejaculate contains up to 1-billion sperm and decreases rapidly after the first semen collection. In this case, XY Inc. researchers were able to sort 46-million sperm on the first day; 21.5-million, the second day; and 27-million, the third day. Dr. Burns used the fresh sperm to artificially inseminate Rose three times over a five-day interval.

"With sperm sorting, early research is a process to learn what precise combination of factors is needed to first achieve live offspring from sexed sperm and then improve accuracy to consistently produce a very high percentage of the desired sex of the offspring," Schenk said.

Dr. Burns explained the use of AI with non-sorted sperm to breed dogs has become an increasingly popular method over the last decade. Each AI dose typically contains 100-million sperm, and over the breeding service several doses are used.

Rose was AI bred with less than 95-million total sorted sperm.

"The low dose and the fact that the sperm were sorted is a 'double first' in the dog-breeding world," Dr. Burns said.

Rose, who is a first-time mother, had no complications during the pregnancy or delivery of the five pups. Dr. Burns noted a typical litter size for a female Labrador is five to 10 pups with a mean of seven. This litter was no exception, with the litter developing normally over the typical nine-week gestation cycle.

Dr. Burns concluded, "Using sex-sorted sperm to artificially inseminate dogs is probably not too practical for typical breeding. However, for specialty breeding, this is a major breakthrough with great potential."

Added Leighton, "The Seeing Eye would find it very helpful if some litters could be produced that are mostly females, and I believe that access to sex-selection technology would be useful to dog guide schools around the world."

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Jasmine Kleine

Jasmine Kleine

Jasmine Kleine is the the online editor at She is an experienced dog owner and professional writer who lives with her two beloved dogs, Mabel and Charlie.


  1. Allot of people are sceptical about this sort of thing were you can choose the sex before it is born, I guess it’s not so bad with dogs I don’t really know, but mucking around with DNA and nature isn’t a great thing full stop, we should just let nature take its course, any way cool post thanks.

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