Humans bred dogs that can’t breathe. Science may finally give them some relief. Frazao Studio Latino via Getty Images Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. Some much-needed relief may be on the way for beloved “ flat-faced” dog breeds . After over 15 years of research, a team of scientists from the Royal Melbourne Institute of Technology in Australia and biotechnology company Snoretox have created a new treatment they say can ease breathing in flat-faced dogs . Called Snoretox-1, the new injectable treatment uses a modified version of tetanus toxin. It is  placed directly into the dog’s geniohyoid muscle—in the inside of the mouth, on top of the throat area.…