LONGMONT, Colo. — Colorado livestock owners are on high alert. A painful virus is spreading among horses, and there are concerns it could soon be transmitted to cattle, pigs and possibly humans.

The virus is called vesicular stomatitis. It makes it difficult for animals to eat or drink.

“It’s pretty nasty. They get blisters on their mouths and sores on their tongues,” explained Rachel Corbman, with Colorado Horse Rescue in Longmont.

Colorado Horse Rescue hasn’t seen any confirmed cases of the virus, but employees and volunteers are carefully monitoring for it.

Colorado saw its first confirmed case on July 3.

The Colorado Department of Agriculture is now investigating the possibility of more than 120 cases statewide, and animal quarantines have now been ordered for 52 properties, most in Larimer, Weld and Boulder counties.

“It started in Texas. Five days later, it showed up in New Mexico, five to seven days later, here in Colorado,” said Nick Striegel, the assistant state veterinarian with the Colorado Department of Agriculture.

The virus is most often transmitted by flies. Symptoms usually exhibit themselves for about a week.

So far, Colorado cases are only affecting horses. However, in 2015 (the last time Colorado saw a major outbreak), cows and pigs also contracted the virus. In rare cases, humans can also be infected.

“It’s kind of odd because you can have a stable of 15 to 20 horses and maybe there’s only one affected, and you can have a stable or horses where’s it’s just popping up in all of them,” said Striegel.

Striegel says one horse owner in Colorado is currently dealing with 38 infected horses.

Colorado Horse Rescue has not seen any cases, but there is a confirmed case just down the road, which is why the non-profit is staying vigilant and looking for any signs that something isn’t right.

“You hate to see your animal get sick, especially when it’s nothing you have control over,” said Corbman.