After two New Mexico horse were confirmed as suffering from Vesicular Stomatitus last month in Otero County, an undisclosed number of new cases have cropped up, and New Mexico animal health officials say they are heightening safeguards to prevent the disease from spreading further.

Eleven premises spread across six counties are under quarantine now and two additional counties are “under watch” this week after new cases of VS were confirmed by the New Mexico State Veterinarian’s office. Confirmed cases have surfaced in Otero, Valencia, Socorro and San Miguel counties and suspect cases exist in Dona Ana and Roosevelt counties. Animal health officials say Santa Fe County and Bernalillo County are also considered high risk for the disease as well.

Effective immediately New Mexico officials are requiring a written  health certificate (CVI) for all New Mexico livestock, including cattle and horses, that travel to public events including roping, racing, breeding, and other forms of public exhibition where out of state livestock are a part of the event. The certificate must be less than five days old at the time of any public event and the rule includes all animals being transported interstate.

According to a statement from the state veterinarian’s office, “the animals represented on the certificate must not have originated from premises or areas under quarantine for VS or from premises where VS has been diagnosed in the past 21 days.” A veterinarian must note on the certificate that the animals were examined for signs of VS and certify that no lesions or clinical signs of VS were discovered.

In Texas, the Texas Animal Health Commission (TAHC) prohibits movement and entry into the state if livestock originated from quarantined areas and also requires a valid certificate of veterinarian inspection before inbound livestock can cross the state line.

VS is a viral disease that primarily affects horses and cattle and occasionally swine, sheep, goats, llamas, and alpacas. Humans can also become infected with the disease when handling affected animals, but this is a rare event. Vesicular stomatitis has been confirmed only in the Western Hemisphere. It is known to be an endemic disease in the warmer regions of North, Central, and South America, but outbreaks of the disease in other temperate geographic parts of the hemisphere occur sporadically.