interesting article, page-2

All natural heparins are now sourced from pig intestines. That includes the full length heparin Baxter was selling and the low molecular weight heparins like enoxaparin. They used to be sourced from Cattle as well but since mad cow disease that supply source has stopped.

The issue with the Baxter material seems to one of quality control. That's a very difficult issue when the product is extracted from animal sources because the heparin comes out as a complex mixture (like crude oil). It is not yet certain whether that is at source or in the US (though I bet there will be a lot of finger pointing going on).

Fortunately for Alchemia, fondaparinux is a synthetic heparin and can't suffer from animal contamination issues. It will be interesting to see how much of the market moves to the safer fondaparinux option in light of the recent problems with pig heparin. Fondaparinux certainly seems to have a market advantage here.