Well, now that we've got exhentai in the mix in the thread below, I've taken some time to dig around for tf manga. There's one there called "[Nanamehan (Hansharu)] Pet Life After Fusion 2 [Digital]", by Hansharu.
http://http://exhentai.org/g/623840/54f8275de9/ It's in moonspeak, so the tf's may not be to everyone's tastes, as I can't exactly figure out the circumstances. Appears to be a pair of girls, one into a cow, the other into a piggy, while a friend appears, already having been changed into a dog, watches their forced transformations. Might be a little corruption at the end as well, not sure. As this is number two in the series, I'm wondering if there's a #1 hanging around out there to download, or perhaps a #3. Also wondering if there's a translated version, preferably to English. I dug around exhentai and gehentai, but no luck there; did a quick google too, but no joy.... Thanks!