Inbreeding. But prob not as bad as the British Royals.
DF
There are some that think having them neutered too soon may also contribute. Neutering was mentioned in the link.
I have a couple shorthairs and emailed them to see if they do the testing on shorthairs. Their response:
“ Currently, our testing is only available for labrador retrievers because that is what our reference population is made from. We are actively working on expansing the testing to more breeds, but there is no current timeline for when it will be ready.”