An experimental drug appears to prevent dangerous blood clots, without raising the risk of excessive bleeding -- at least in animals, Newsmax Health reports.  

Scientists found that an injectable antibody protected rabbits from developing blood clots but didn't cause bleeding complications -- a potential side effect of all current anti-clotting drugs.

The hope is to eventually bring safer drugs to the market, said researcher Dr. Thomas Renne, of the Karolinska Institute in Stockholm, Sweden.

Renne said his team plans to test the antibody, dubbed 3F7, in a phase I study -- a small trial that tests the safety of a drug in humans.

The antibody effectively blocked clot formation in rabbits that were placed on a simulation of a heart-lung device. It worked about as well as heparin, the researchers found, but without causing bleeding.

Anti-clotting drugs are commonly used outside of hospitals, too. Many people take oral medications, such as warfarin (Coumadin), to prevent clots that could lead to a heart attack or stroke.