Test Tube Puppies Born Via IVF Could Help Preserve Endangered Canine Breeds

The world's first litter of test-tube puppies is frolicking, playing with toys, and doing all manner of puppy things after scientists solved the mystery of in vitro fertilization in canines.

The seven puppies, two from a beagle mother and cocker spaniel father and five from two beagle parents, were born in the spring. Researchers at Cornell University and the Smithsonian Institute worked together on solving what the university called a "decades-long puzzle" on why in vitro fertilization techniques weren't successful with dogs.

In a study published in the open access journal Public Library of Science ONE on Wednesday, researchers detailed what they changed in their in vitro process to achieve fertilization.

Successful IVF in mammals typically involves retrieving mature eggs and sperm, combining them to produce embryos, and then transferring them to a female host at an appropriate time during her reproductive cycle, Cornell said.

But dogs' reproductive cycles are different from other mammals'.

"Canine eggs retrieved at the same stage of cell maturation as other animals failed to fertilize," a Cornell statement said. Research biologist and paper co-author Nucharin Songsasen worked on proper timing to retrieve the egg, and the team also reproduced the conditions of the female canine tract in the lab. Making those process changes resulted in fertilization rates of 80 to 90 percent.

The technique isn't important because the world needs more puppies, according to NBC News. Scientists will, however, be able to help dog breeds that are on the brink of extinction and they may also eventually be able to rid dogs of diseases through gene editing.

"There's currently five species of dog that are threatened with extinction," lead researcher Alexander Travis told NBC. "They include the red wolf, the African painted dog, and the Ethiopian wolf. So by doing this now in a domestic dog, what we're doing is creating a platform or starting place to now expand this technique to be used for all these other species of dog. It may not turn out to be exactly the same, but it gives us a really good starting point."

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