Canine Ergonomics: The Science of Working Dogs, is due out later this month from CRC press and was written by William Helton (who was, coincidentally, a classmate of mine in grad school). The book is an attempt at bringing disparate perspectives together into a definition of canine ergonomics, with topics including the role of dogs in mine detection, search and rescue and assisting people with disabilities.
Also see the related interview, Canine Factors & Human Factors: An Opportunity for Collaboration?, from the Human Factors & Ergonomics Society.