If you think having a child using artificial fertilization is hard, try having a puppy. Dogs’ reproductive systems are so quirky that researchers have been trying—without success—since the 1970s. But now, scientists have used a new set of techniques to give rise to the world's first “test tube puppies,” a litter of beagles and beagle mixes that can trace their start to eggs and sperm in a petri dish. To bring the new litter into the world, researchers collected mature eggs from the canine equivalent of the fallopian tubes, a trickier prospect than collecting them from ovaries (as is done in humans). Once they had the eggs, the team experimented with different conditions for fertilization and incubation, finally coaxing seven embryos to grow in a surrogate mother hound, they reported yesterday in PLOS ONE. The pups, now 5 months old and thriving with their adoptive human families, could offer hope for endangered species like red wolves and African wild dogs, the researchers write. Dog in vitro fertilization could also be used to study heritable traits and diseases, many of which are shared by both dogs and humans.