North Dakota's state veterinarian is urging ranchers to protect their animals against anthrax.

Susan Keller says an anthrax case has been confirmed in eastern Sioux County - the first in that area in many years. It also is the first confirmed case in the state this year.

Keller is urging ranchers to make sure their animals are properly vaccinated.

Anthrax bacteria spores lie dormant in the ground and become active under conditions such as heavy rainfall, flooding or drought.

North Dakota usually has a few anthrax cases every year. In 2005, the disease resulted in an estimated 1,000 dead cattle, bison, horses, sheep, llamas and farmed deer and elk.

Copyright 2010 The Associated Press.