And actually, Thalidomide was very thoroughly tested on a variety of species.

And Dr. Kelsey apparently saw something in those test results that the governments of a bunch of other countries didn't (though not specifically about birth defects as I recall) and refused approval, leading to pressure on the FDA to approve the drug in the US as it was internationally, rather than waiting for further testing. I mean if I'm wrong about that do feel free to point out something other than the official line.

And yeah, it's apparently a good drug for other things.