As an undergrad student, I helped conduct a paste-diet study for NASA. The ideas was that rats who would be aboard the space shuttle would eat a combined meal of rat food mixed with water, thereby solving the problem of little bits of food floating around space compartments. I have assumed since that time that there would be continued experiments regarding animals in space, including the ISS, but I have never followed up on this.
My guess is that it's too messy and too time/resource consuming to do cleanly.
Also the ISS is in microgravity. IIRC Mars has something like half the Earth's. Moon would be a better testbed.
Mice are small enough that you could probably simulate Martian gravity with a smallish centrifuge. Plus, if they don't have any developmental problems growing up in zero gravity, you can probably safely assume that 1/3 Earth gravity is going to be OK.