Researchers from Cornell University’s College of Veterinary Medicine and the Smithsonian Institution have solved the decades-long puzzle of in vitro fertilization in dogs, resulting in the world’s first litter of IVF puppies.
The study, “Live births from domestic dog (Canis familiaris) embryos produced by in vitro fertilization,” appeared Dec. 9, 2015, in the online journal PLOS One.
Researchers at Cornell transferred 19 embryos to a female hound, which gave birth in spring 2015 to seven healthy puppies. Genetic testing shows that two of the puppies are from a Beagle mother and a Cocker Spaniel father, and five are from two pairings of Beagle fathers and mothers.
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The researchers found that canine eggs failed to fertilize if retrieved at the stage of cell maturation associated with fertilization in other animals. When they left the eggs in the oviduct for an extra day, however, the eggs reached a stage where fertilization was more likely to occur.
In addition, the female dog’s reproductive tract plays a role in preparing sperm for fertilization. The researchers found that sperm could be artificially prepared by adding magnesium to the cell culture.
The study is available here.