I know for a fact those drugs can affect your animal. I saw the most fight crazy dog you would ever want to see get bred naturally. When the guys said they were going to breed him i asked if they were going to collect him and do an A.I. breeding they said no. I told them they would never be able to breed him like that and they said just watch. The administered a few cc's of dex and about 45mins later the dog looked confused and a lot calmer around the gyp and they got him bred and the bitch took.