Sporting greyhounds? You mean they don't all race...
The litter outlaws come last but not least, of the so called half/half mostly present in America, but scarcely seen to pop up with little success between tight communities of show hobby breeders in Europe or elsewhere. The once that try to have it all. Run the course, trot the show, race the track and be as loved in a home as the rest so desire.
They tend to be slower than the racers, smaller than the courser and certainly not as majestically posh as the showlines and they are rarest as it seems!
Due to close line-breeding with time the inevitable happens and the genetic diversity of a population once healthy starts to decrease the longer the years roll on by.
This is the case at the moment with the show bred greyhounds, it starts to have effects on the racers, especially closely bred Australian lines and some Irish lines with lesser degree to the USA lines due to not so close breedings in the past 30-50 years and so it goes. The genetic pool closes further due to the use of the popular sires with over 3000 offspring like Top Honcho, Brett Lee, Honcho Classic...the list goes on.
No, it is not just the closely bred (inbred) show dogs that exhibit health issues, we see problems in the racers like heart issues, skin, neurological and digestive issues, eye issues like panus and un-decended testicles. These are mutations in genes and some of the way they are passed on is not fully clear as the few cases for which we may have DNA tests already. Greyhound Neuropathy GHN is hardly the issue in showlines at the moment and since it is fully testable via a simple DNA test, there is nothing to worry about since we have tests.