Horses are primarily affected by VS, however many livestock species are susceptible. Yearly insect migrations are considered to be the major source in spreading the disease with livestock transportation also playing a role. Based on the mechanism of disease spread, prevention is the best management practice, especially for horse owners. Daily fly control, especially on the ears, is recommended for disease prevention. Due to the severe outbreak of 2014 with 370 quarantines, the State Vets office is urging livestock owners to practice disease prevention.
For more information on VS, visit the Colorado Department of Ag website at
or the USDA website at