If you look at the news, a week or two ago Spanish police raided this huge operation that was selling doping to amateur athletes. I've heard from amateur athletes themselves too how pervasive doping is. My feeling is that if it's common in places where there's little to no money to be made, that it's going to be near universal in sports where there's a lot of money going around and doping testing is weak (like in football or tennis).
Same feelings, sport as a whole has felt pretty empty to me since reading the full details of the USADA report on Armstrong and the whole Fuentes fiasco. Football has virtually no drugs testing, some players may have their urine tested maybe 2-3 times in their whole career. Tennis is a total joke.