I'm sure there's more than one way to draw a cat-like creature, especially when the Lyran is pretty much hairless and has batlike ears (surprisingly looking more like descriptions of Nevin's Kzinti from his non-Trek books). They surely find ways of drawing human looking folks in different ways (Klingons, Vulcans, Romulans, Humans...).
Of course having been through these discussions before, and doing a quick search using the words "Mirak" and "canine" you'll find a lot of references about Taldren making an effort to make them more dog like. I believe there were even comments about it from the devs at one point on the old boards, but my memory is such, anymore, that I can't remember exactly what was said. Heck, there's even fan fiction written with Mirak being canine. You'll find comments like:
"Due to licensing concerns, Star Fleet Command altered the Kzinti into the more canine Mirak."
as well as
"and probably why the Mirak were given canine/wolfman qualities as opposed to feline"
and
"
I'm guessing that Taldren decided to make the Mirak and Lyrans mortal enemies by making the Mirak K9(?). Totally relieving themselves of being accused of copying the Kzinti from a licensing point. Can you say, "smoke screen"?
As a sidebar, there was a race in SFB that was K9. They were located in the section of space between the Lyrans and the Kzintis. They were wiped out shortly after warp drive was discovered by their neighbors. Go figure! "
Now, You'll also find reference to them being feline at some sites, and fan fic. Such as Mobygames saying:
"The other feline race, the Mirak (Kzinti), rely heavily on missile-armed ships, with often devastating effectiveness."
Now, this could be explained by the fact that game reviewers usually pay about 2 seconds of attention to the game, and having any knowledge of the source material (he references the Kzinti) probably lead him to the assumption that their replacement would be feline as well.
A preview at Gamespot (and other places) mentions them being feline, but they also call the online multiplayer universe the "metaverse" and not the later adopted name of "dynaverse", so it was obviously not in a finished state when the article was written.
In reality, though, most if not all (and I would venture to say all left playing at the very least) Mirak players tend to think of themselves as Kzinti and feline, completely disregarding the copyright dodge and just going with SFB history, even if they do occassionally say Mirak (although I don't venture into the D2 forums much anymore, it's been a while since I saw anything but Kzinti, I believe). Personally I like to think of them as feline as well, but I believe they were intended to be canine (an idea which I always hated).