Even before Laika set paw in Sputnik 2, Soviet researchers sent dogs into higher altitudes than any canine creature had traveled before. To help keep those dogs safe—and to test the equipment that would allow humans to eventually reach orbit—these scientists created high pressure suits, complete with helmets fitted to dogs' heads.
Retronaut posted a handful of photos of the early high-pressure suits, which give us a sense of how well they fit those aerial pooches (not terribly well, in some cases). Sadly, only a handful of these suits remain; the rest have fallen apart over the decades. The tan suit with the laces is currently on display at the National Space Centre in Leicester, England. The Guardian has a video of the suit arriving at the Space Centre and space communications manager Kevin Yates discussing the history of these proto-space suits.
Personally, I'd be interested in seeing footage of the dogs donning these suits for the first time. I'd imagine that for many pooches, being enclosed in a clear helmet and muffling suit was as disorienting as being launched from Earth.
Dog Space Suits [Retronaut]