Looking for title of sci fi short story about attempts to colonise planet (Venus?). Scientist and his dog are main characters

They want to see if humans can survive in harsh planet conditions with a view to future colonisation. Scientist guy invents a machine which can transform humans into beings which are adapted to conditions on planet. They send folks in but none ever report back. Scientist, in despair, sends his old dog in. Dog doesn't return either so scientist finally goes himself. Gets to planet and, in his new state, finds himself strong and perfectly adapted to life on new planet. Meets his old dog who is also fine, they can now communicate and end up going off to discover the new world together.