Coyotes are the single biggest predator of sheep, responsible for nearly half of all predator kills in the United States. But they’re far from the only threat. Domestic dogs, wolves, mountain lions, bears, eagles, and foxes all prey on sheep depending on the region. Outside North America, dingoes, wolves, and lynx fill similar roles.
Coyotes: The Leading Threat
Coyotes account for 46.9% of all predator-caused sheep deaths in the U.S., making them the dominant predator by a wide margin. They hunt both individually and in small groups, typically attacking from behind and targeting the throat or hindquarters. Their bite marks are relatively small, with canine tooth punctures about ⅛ to 3/16 of an inch in diameter, and they often need to readjust their grip multiple times during an attack.
Interestingly, not all coyotes are sheep killers. Research from Oregon State University found that the coyotes responsible for livestock kills tend to be older, bolder breeding adults trying to feed large litters when natural prey is scarce. Subordinate coyotes in a territory rarely go after sheep. In fact, when a breeding pair of coyotes holds a territory and leaves livestock alone, their dominance actually keeps sheep-killing coyotes out of the area. This is one reason wildlife managers increasingly favor non-lethal deterrents over trapping, which tends to catch the non-offending animals first.
Domestic Dogs Are the Second Biggest Killer
This surprises most people: pet and stray dogs cause 33.9% of predator kills on sheep in the U.S., making them the second-largest threat after coyotes. In the UK, the problem is severe enough to have its own term, “sheep worrying,” and the numbers are climbing. An estimated 15,000 to 18,500 sheep are killed by dogs annually across the UK, costing farmers over £1.6 million per year. Dog attacks on sheep in Scotland alone quadrupled in recent years, and the National Sheep Association estimates that 20 to 25% of its members have dealt with dog attacks on their flocks.
Unlike wild predators that kill to eat, dogs often attack sheep out of instinct and excitement. A single loose dog can injure or kill dozens of sheep in one incident, and many of the sheep that survive an attack later die from stress, infection, or miscarriage if they were pregnant.
Mountain Lions, Wolves, and Bears
Mountain lions (also called cougars) account for about 4.3% of predator kills on sheep in the U.S., concentrated in western states. They’re ambush hunters that use their powerful front legs to hold prey while delivering a killing bite to the skull, spine, or windpipe. Unlike coyotes, mountain lions are strong enough to maintain their grip without readjusting, leaving large, clean puncture wounds and narrow claw marks with smooth edges.
Cougars also cause indirect damage that doesn’t show up in kill counts. A 48-year study of bighorn sheep in Alberta found that during years of intense cougar activity, lamb production dropped 14.2%, females gained 15.6% less weight over summer, and lambs weighed 8% less at weaning. The stress of living near an active predator takes a measurable toll on the entire flock, even on animals that are never attacked.
Wolves chase their prey over long distances, inflicting repeated bites that cause blood loss and exhaustion. Their blunt canine teeth create deep tissue damage, especially on the hindquarters, flanks, and near the tail. The worst of the injury is often hidden beneath the skin. Bears rely on brute strength rather than precision, and while they’re capable predators, they’re omnivores that typically turn to sheep only as easy, opportunistic prey.
Eagles Target Newborn Lambs
Golden eagles prey on lambs, but their impact is limited by simple physics. A male golden eagle weighs about 3.8 kg (8.4 lbs) and a female about 5.3 kg (11.7 lbs), and an eagle can only carry prey roughly equal to its own body weight. Since the average newborn lamb weighs about 4 kg and quickly grows past 5 kg within weeks, the window of vulnerability is narrow. Eagles scavenge small lambs in spring (April through June) and occasionally take larger lambs in autumn, though they can’t carry anything much heavier than a few kilograms any real distance. Eagle predation on sheep is real but accounts for a small fraction of overall losses.
Predators in Australia and Europe
In Australia, dingoes and feral dogs have been devastating to the sheep industry for well over a century. Historical records show losses of staggering scale: in 1882, just 47 stock owners in South Australia reported losing nearly 258,000 sheep to dingoes over three years. By 1910, annual losses reached 100,000 sheep in a single state. At the worst points, some flocks lost 20% of their animals per year. The threat was so severe that Australia built the Dog Fence, one of the longest structures on Earth, stretching over 5,600 km to keep dingoes out of sheep country.
Europe has five large carnivore species that can threaten sheep: wolves, brown bears, Eurasian lynx, wolverines, and golden jackals. Wolves are the primary concern for European sheep farmers, particularly as wolf populations recover across western Europe. Brown bears, despite their size, are not especially skilled hunters and feed mostly on berries, plants, insects, and carrion. They do target sheep in some regions, but it’s opportunistic rather than habitual. Wolverines are a significant threat in Scandinavia, where they also prey heavily on semi-domestic reindeer.
The Economic Cost
Predation adds up quickly. In Utah alone, predators killed 4,700 sheep and lambs in 2024, with losses valued at $1.187 million. Scale that across every sheep-producing state and country, and the global cost runs into hundreds of millions of dollars annually. These numbers also undercount the real impact because they don’t capture the stress-related losses: reduced fertility, lower weight gain, and higher lamb mortality in flocks that live under constant predator pressure.
How Farmers Protect Their Flocks
Livestock guardian animals are one of the most effective and widely used defenses. Guardian dogs, bred specifically for the job, live with the flock full-time and aggressively repel predators. Llamas serve a similar role through different instincts. When they detect a threat, they alert the flock with alarm calls, position themselves between the sheep and the predator, and will chase, kick, and paw at intruders. Donkeys are naturally suspicious of anything unfamiliar in their environment and will bray, bite, and kick at predators that approach.
No single guardian animal works perfectly against every predator. A llama may deter a lone coyote but won’t stop a pack of wolves or a mountain lion. Most producers use guardian animals as one layer of protection alongside fencing, night penning, and other measures tailored to the specific predators in their area.