For thousands of years, humans have been tinkering with the health of dogs. From pointy-eared, sharp-faced wolf-like ancestors, we’ve shaped generations of canines into distinct breeds with unique features such as flat faces, stumpy legs and long silken hair.
But all that low-tech genetic engineering has taken a toll on the health of many modern dog breeds. Bulldogs, for example, sometimes struggle to give birth without surgery or additional assistance. Other dog breeds are known for being prone to hip dysplasia, heart conditions and eye problems.