About 20 years ago. There was a group of people who approached me do some donating of blood from my dogs to test what all breeds of dogs were in them. They were trying to see what outside blood might cause them to bite people. Yet the test didn't fix the problem. I never had taken blood from a dog before. So I contacted a friend of mine who worked for a vet. We took blood from my dogs and several friends dogs. Now all the dogs that were tested had trash in them at that time. My abe dog was almost pure with minute parts of Terrier. He had like 1/1000 outside blood. Most of the outside blood in the dogs were English,Boston,Boxer and other bulldog types. There were some with different blood of Terrier types. The trashest were the Mayday dogs and I'm not running them down. They are as game as any other bloodline of dogs today. This trash didn't seem to hurt their gameness and they just had minute amounts of the outside blood. They had Lab and retriever in them. I had three Mayday dogs here from different yards. They all had the Lab and retriever in them. One dog that was tested belonged to a friend of mine. He was a two time winner and was Boudreaux and Nigger on his pedigree and he was tested. His blood showed to be a mix of Bulldog and terrier but had none of the origional pitbull blood. They used Amstaffs as a guide to the pure blood. The Amstaff's test showed they had no outside Bulldog or Terrier blood in them. So they were used as part of the test. Some of the Boudreaux' dogs I had here also tested pure except for added bulldog blood. There were five pitbulls that were littermates tested at one Kennels and they all tested slightly different in their inherited outside blood. Now again I am not running any bloodline down. I will say that picking up dogs off the street that were good game dogs and breeding to them caused this outside blood. Anyway I can prove this was all done but still believe there are good game dogs in all bloodlines. I believe it doesn't matter what outside blood they have but it bothers me a little to know the truth. I talked to the Tester the other day and the test has been improved and they have found new markers. This means the test is correct except some new outside markers have been found so there may be more outside blood than the first test showed.