New book and article by Lynne Sharpe. I haven't read it but looks interesting and was recommended by Mark Bekoff on his ethological ethics email list. The last book I read that he'd recommended (Empty Cages by Tom Reagan - will try to post something about that one at some point when have time) was fab.....
http://www.animalaid.org.uk/campaign/pride/sharpe.htm
http://www.imprint.co.uk/books/sharpe.html