Colorado’s first anthrax outbreak in a generation is being investigated on a Logan County ranch, the state government has confirmed. Anthrax, an infection caused by the spores produced by Bacillus anthracis, has reportedly killed at least 50 head of cattle on the Colorado ranch.  “The risk is minimal outside the affected ranch, said said State Veterinarian, Dr. Keith Roehr in a statement Wednesday. “We believe, at this point, that anthrax is confined to that specific premises. Colorado has not had an anthrax case in 31 years but anthrax outbreaks are not uncommon in the Western United States. We are dedicated to providing the necessary response to ensure that the investigation works quickly to limit the spread of this disease.” Only bovine infections are likely to arise from the Colorado outbreak, but humans can become infected with anthrax by either breathing spores from infected animal products or eating undercooked meat from infected animals. Foodborne or gastrointestinal anthrax is rare. Colorado has placed the ranch involved under quarantine and notified surrounding ranches about the outbreak. The affected ranch is located northeast of Sterling, CO. No cattle left the ranch before the quarantine and no infected cattle entered the human food supply, the state veterinarian said. The anthrax was confirmed by a necropsy performed on a dead animal by the Colorado State University Veterinary Diagnostic Laboratories.Cattle, people and equipment are all monitored to prevent the disease from leaving the quarantined ranch. “Our focus is on the potential for human exposure,” said Dr. Tony Cappello, district public health administrator for the Northeast Colorado Health Department.  “We are currently conducting our own public health investigation and contacting individuals that have been involved with the livestock. Anthrax is not spread from person to person and exposure is limited only to those who had contact with the affected cattle or the immediate area.” During a drought like the one now affecting eastern Colorado, spores can develop naturally in the soils of riverbeds. During periods of rain or flood, these spores can become active and kill many animals quickly, often before anyone realizes they are infected. Ranchers are being encouraged to take care not to further contaminate soils when burying carcasses, and to check with their veterinarians about when anthrax vaccines would be advisable. Cattle, sheep, goats and horses are all susceptible to contracting anthrax. If caught quickly, animals are treated with antibiotics. The largest recent anthrax outbreak involving humans came in 2001 when it was made into a powder and sent through mail to its victims — 22 people in total.