Scientists have successfully impregnated a dog using IVF (in-vitro fertilization), and her litter may be key to saving endangered fox and wolf species.

The news of the first ever IVF litter was announced by researchers from Cornell University. The reason for it being such a breakthrough is the difficulty of the process: dogs have a unique reproductive system that makes IVF very tricky.

“I like to say it’s because dogs are weird. … They have a lot of fun, reproductive quirks. They experience really long periods where they don’t cycle. They go into heat once or twice a year,” Jennifer Nagashima, lead research author, said.

Scientists implanted 19 embryos using a complex technique: they surgically removed eggs from donor dogs approximately six days after ovulation and then fertilized them with sperm collected from male donor dogs. They subsequently froze the embryos before finally implanting them.

Seven puppies were born, giving hope that this could be a step towards saving endangered canid species such as the red wolf and the African wild dog.

The pups are a Beagle and Cocker Spaniel mix and all have now been adopted. One of the puppies was named Ivy after the IVF method.