Title: Wandafuru (Woof-derful)
Mangaka: Morinaga Milk
Warnings: adult content, i.e. nudity and suggestions of sex (yuri, het, implied bestiality)
ISBN: n/a

Just when you thought Morinaga Milk couldn't get any weirder...
The main character of this story is a dog. Sometimes she's depicted as a dog, and sometimes as a human. There are undertones of bestiality but no sex involving physical animals is actually shown.
The title, "Wandafuru," is a play on words-- it's the English word "wonderful" but the "wan" part is also a pun on "wanwan," the sound of a dog barking, which is also a cutesy word for "dog."

It's spring, a "wandafuru" time of year-- the season of love. Choko, a dog, goes out on a date with her boyfriend (also a dog), Daisuke. Choko's dream is to have lots of kids with Daisuke.
But the truth is, the person she loves most is her mistress, Kanako. She wants to have kids with Kanako too!
At the very end, she thinks/says, "Just hold on, Kana-chan, we'll be able to meet each other [with both of us in human form] soon!"
Though the end says "next coming soon," this is the only bit I've found of this.
Every image of this (there are only four pages) had adult content, so I'm just posting parts of pages.