A man holds a sign during a "Dogs Against Romney" demonstration outside the 136th Westminster Kennel Club Dog Show at New York's Madison Square Garden, on Tuesday. Shannon Stapleton /Reuters/Landov hide caption

itoggle caption Shannon Stapleton /Reuters/Landov

Breeding sows in crates at a subsidiary of Smithfield Foods in 2010. The photo was shot by the Humane Society as part of an undercover investigation. Humane Society/Associated Press hide caption

itoggle caption Humane Society/Associated Press

A chimpanzee eats a coconut at the Alamogordo Primate Facility at Holloman Air Force Base, N.M., in an undated photo from the National Institutes of Health. A plan to move chimps that had retired to the facility after being subjects of medical experiments sparked controversy and a review of research policies. AP hide caption

itoggle caption AP