The highest number of bison in the park was 4,900, in 2005. Despite a summer estimated number of 4,700 in 2007, the number dropped to 3,000 in 2008. That was after a harsh winter and a controversial brucellosis management when hundreds were sent to slaughter. The Animal and Plant Health Inspection Service (APHIS) has stated that with vaccinations and other means, brucellosis can be eliminated from the bison and elk herds throughout Yellowstone.