Yes. Heparin can be isolated from the intestinal mucosa of most mammals. The predominant source is swine. There used to be a fairly large market from beef, but mad cow disease led to the move to swine. There is some horse and some sheep sources as well. The regulation of the materials has been quite tight but there is some reason to believe that the adulteration was intentional and designed to evade the analyses (essentially put the thumb on the scale). Long term, I think purely synthetic approaches will replace animal sources, but we are a pretty good distance from that point.