I know some people here at TN have done envirovet. It looks like it's through UIUC vet school. Everyone I've known who has done it has come away with really positive things to say about it.
the Canadian chapter of Vétérinaires sans Frontières is run through the Ontario Veterinary College (Guelph), and while it has recently started up, it is very active and has a number of programmes and initiatives.
I had forgotten about that. We had someone from there come and speak here at UTK. It sounds like an awesome program, and the student who did it was really enthusiastic about it.