Anthrax has killed 56 cattle and four horses in North Dakota since late July, and in Clay County, Minnesota, officials say the bacterial disease has infected livestock there for the first time in 100 years. Anthrax occurs in nearly all species worldwide. Jim Collins, doctor of veterinary medicine and Director of the Minnesota Veterinary Diagnostic Laboratory, says it is very deadly and kills animals quickly. The bacteria releases toxins that destroy the infected animals' cells.