"Kreb" (WARNING: CONTAINS SCAT AND FARTING IN SOME PARTS)
http://www.docs-lab.com/submissions/765/kreb
Everyone in the world TF's into anthros in spurts over a 24hr period due to an alien meteor of sorts. Only close relatives TF to the same species so virtually all couples break up from being incompatible species. The story mainly focuses on a man who becomes a dog anthro and his wife who becomes a sow anthro. The pig TF parts is where the flatulance and scat comes in at.