A jogger who was head-butted and trampled on by a herd of cows has been rushed to hospital with serious injuries.
The frightening incident happened on the Meadowlark Trail in Colorado, US, while out running over the weekend, according to a Boulder Park Country Parks & Open Space spokesperson.
Vivian Kuenn, who was biking down the hill when the jogger was running along the trail, said she saw a herd of cows surround the woman before she started screaming.
She told 9News: "She screamed and was just down on the ground while they were just trampling her.
"In a very short span of time she stopped moving. At that time I thought, oh gosh, did I just watch her die? Which thankfully wasn't the case."
Vivienne Jannatpour, Boulder County Parks and Open Space spokesperson, told CBS: "It was a surprise, but we do know mother cows can get agitated."
Meanwhile, a second runner was also head-butted by the cows in the week but thankfully the individual was not seriously injured.
According to officials, at the start of the trailhead, there's a sign which says "Give cows space. They can be aggressive."
Park staff believe the mothers were protecting their young when the scary incident happened.
Mike Foster, the agricultural division manager for Boulder County Parks and Open Space, said the department put up the sign as it is calving season.
He said: "We want to inform the public and help reduce risk between, and interaction between, the public and livestock when they are out grazing. "
Mr Foster revealed he helps manage 25,000 acres of land that the parks owns and releases properties to tenants.
He added the cows had been there long before the trail.
The manager said: "Livestock can be very aggressive during calving season, and we are in calving season.
"Just like a momma bear elk or moose, a momma cow is going to be very protective of its young. And when they perceive a threat they are going to react to that threat."
He doesn't believe the jogger did anything wrong as she stayed on the trail but if someone approaches cows quickly the animals may see it as a threat.
"What we advise is give cattle a wide berth," Mr Foster said. "If cattle are standing on the trail it's better to run around and wait in your car for a little bit until cattle move off the trail."
Due to the incidents, parts of the trail have now closed.
