Obviously, I mean any living organisms from the animal kingdom except humans, sent to the International Space Station (ISS) for the purpose of scientific research. I also don't mean if they did the Chicken Run on their own. Clearly, that wouldn't be possible, so fear not, while I realize this might so far sound like an attempt at trolling, my motivation for asking this question isn't to impose my moral views, ask stupid questions, or anything like that. I'm asking this question to understand better the extent of medical and biological research performed onboard the ISS, and whether studies also continue post-exposure to microgravity and increased radiation conditions on the station, to study readjustment to gravity, the ability of subjects to regenerate under different medication regimes, and so on.
Where does my question come from? Well, I just watched a video interview with Dr. Julie Robinson, NASA's International Space Station Chief Scientist explaining some of the upcoming science experiments planned to be conducted on the ISS in 2014. And among other set goals for the year that barely started, she mentions that more rodents will be sent to the station onboard the third SpaceX Dragon operational cargo delivery mission to the ISS, currently scheduled for February 22, 2014. And we know that rodents and other live animals were already studied onboard Space Shuttle or sent to the ISS before. But here's the thing. Since the retirement of the Space Shuttle, I don't recall any other cargo vehicle also delivering experiments back to Earth, with the only notable exception being the Soyuz spacecraft, but since out of the three of its modules only the crew module actually lands in a controlled manner suitable for delivery of live beings, this means there's only a really limited space available for any experiments to be delivered back alive, where observations could continue. And live creatures tend to require specific conditions to stay alive.
So, since it would obviously be of great scientific value to have at least some of these tiny visitors to the space station return back alive to study their ability to regenerate from their excursion to the outer space (e.g. regrow fractured bones, study effectiveness of medication to regain body and bone mass, blood volume, etc.), I suspect this has been done before, so here's my question:
Which laboratory animals were brought back to Earth alive after being studied in microgravity on the International Space Station, how often was that one of the goals of the scientific research on them, how often did it succeed, when did it last happen, and how severely has the retirement of the Space Shuttle and lack of other suitable cargo delivery vehicles delayed or otherwise affected such research on living animals? Can we expect such research to pick up in pace once commercial cargo vehicles or their capsules (like e.g. Dragon CRS) will also be retrieved on landing and not merely left to burn up in the atmosphere on re-entry?
Perhaps a bit too broad, but covering current success and future plans of a single larger space agency participating in research on live animals (NASA, Roscosmos, ESA, JAXA) onboard the ISS should answer most of my answers sufficiently. I don't expect list answers, an overview should do just fine.