At least six mares in south-central Kansas are part of a growing number of horses in 28 states exposed to a contagious equine disease.
The Kansas Livestock Commission said it contacted owners of the mares this week. Commissioner George Teagarden said his office is still investigating whether other animals could be infected with the disease, contagious equine metritis.
The U.S. Department of Agriculture said 12 stallions and 83 mares in 28 states have contracted the condition since it first emerged in December.
Teagarden said the Kansas mares are traced back to three infected stallions in Indiana.
The highly contagious animal disease can result in temporary infertility and cause mares to abort their young but doesn't affect other animals or humans.