http://www.huffingtonpost.com/2009/10/20/dogs-being-used-to-find-b_n_327976.html
Reporting from Asbury Park, N.J. – Sara pulled on her leash, sniffing up one side of a cluttered bedroom and snuffling down the other. The black Labrador retriever suddenly sat beside an armchair.
Rich Wilbert, her handler, flipped the chair over and poked at the stuffing and seams. He spotted pin-sized drops of human blood — clear signs of an infestation of bed bugs in the small apartment.
Read the entire article: http://articles.latimes.com/2009/oct/21/nation/na-bedbug-dog21