One of my favourite erotica authors is Lora Leigh who started out writing for Ellora's Cave but some of her books are being printed by Berkley, and has also sold to St. Martin's. She's written a series of books about several races of what she calls 'Breeds'. Scientists in her world secretly conducted experiments by intersplicing animal DNA with human and raised the results in labs while performing experiments on them. There are several series of books follow the 'Felines', the 'Wolves' and now the 'Coyotes'. They're not shapeshifters, but humans with animal DNA, and a few interesting ... results.
Apparently, and almost frighteningly, scientists in the real world are proposing exactly that in the name of finding cures for things such as Alzheimers, etc. Read about it here. And almost half of Canadians back those experiments. Somewhat scary, isn't it?