Worldwide, sheep, horses, goats, pigs, rabbits, cats, dogs, bison, moose, deer and elk have been reported mutilated with similar bloodless excisions; often an ear, eyeball, jaw flesh, tongue, lymph nodes, genitals and rectum are removed.

Unexplained livestock deaths were relatively unknown until 1967, when the Pueblo Chieftain published a story about a horse called "Snippy" that was mysteriously killed and mutilated in Alamosa, Colorado.

The story was republished by the wider press and distributed nationwide; this case was the first to feature speculation that extraterrestrial beings and unidentified flying objects were associated with mutilation.

[5] A subsequent investigation by Wadsworth Ayer for the Condon Committee [6] concluded that "There was no evidence to support the assertion that the horse's death was associated in any way to abnormal causes".

[9][10][11][12] On June 10, 1973, Cloud County sheriff Fred Modlin warned the public about a series of telephone calls from a caller identifying as a USDA official conducting a survey of herd population and locations.

Its right ear had reported been removed and right rear quarter butchered; Republic County sheriff Bob Blecha argue the death was not the work of predators.

[17] On August 30, a fourth butchered cow was reported, this one on the Larry LeBlanc farm south of St. Joseph in Cloud County; the right ear was again removed.

[28] On December 22, the Kansas Brand Commissioner's office determined that most of the deaths and removal of sex organs were the result of natural causes including predation, "shipping fever" and blackleg.

[29] Modlin and others vocally disagreed with these conclusion and denied that local ranchers would mutilate dead animals for insurance money, calling them "honest and respectable".

[38] Knox County Sheriff Herbert Thompson reported that armed civilians had begun patrols in response to repeated helicopter sightings.

Cloud County Attorney William Walsh told press of a jailhouse informant who claimed to be a former cult member and opined the mutilations were likely the result of devil-worshiping cultists.

[39] Amid the cattle mutilation jitters and drought, Oakland, Nebraska experienced as spate of "beast" sightings as residents feared an unidentified noisy night-time animal.

Theories ranged from a mundane criminal act of homicide, to more fantastical speculation alleging alien abduction due to perceived similarities with UFO-related animal mutilations.

[73] That year, ranchers began reporting dozens of unusual cattle deaths characterized by absence of sex organs, udders, tongues, anus, rectum, and sometimes ears or eyes.

[64] Samples from the animal's liver were found to be completely devoid of copper and to contain 4 times the normal level of zinc, potassium and phosphorus.

This hypothesis was later discarded as subsequent reports from the Los Alamos Scientific Laboratory later confirmed the presence of anti-coagulants in samples[64] taken from other cows mutilated in the region.

[87] On April 8, 1979, three police officers in Dulce, New Mexico, reported a mysterious aircraft which resembled a U.S. military helicopter hovering around a site following a wave of alleged mutilation which claimed 16 cows.

[88] In January 1975, the Minnesota field office of the Bureau of Alcohol, Tobacco and Firearms (ATF) launched their own investigation into the phenomenon, headed by Agent Donald Flickinger.

[61] Beginning in May 1979, an investigation was funded by a $44,170 grant (equivalent to $185,400 in 2023) from the Law Enforcement Assistance Administration, and was headed by recently-retired FBI agent Kenneth Rommel.

Rommel (a former FBI bank robbery expert) was disgusted by dead necrotic cows and chose to let others do the actual investigations while he waited upwind in the car.

[64]: 25 While many unconventional explanations have been put forward to explain cattle mutilations, a variety of scientists, veterinary workers, and knowledgeable observers (including farmers and other agricultural workers) have suggested more conventional ideas, most of which revolve around the hypothesis that "mutilated" animals died of natural causes and were subjected to known terrestrial phenomena – including the action of predators, parasites, and scavengers.

[104] Kelleher argues there was an "uncanny resemblance between the pattern of organ removals that were taking place in cattle mutilations and standard wildlife sampling techniques for monitoring the spread of infectious agents in the wild.

In July 1975, reporter Dane Edwards of the Brush Banner published a cattle mutilation story and began investigating a theory that a cult was responsible.

On October 9, 1975, a motorist on U.S. Highway 95 in northern Idaho, in an area of frequent cattle mutilation, reported to police that some 15 masked individuals formed a roadblock with linked arms, forcing him to turn around.

Based on information provided by a supposed-insider source called "Rick Doty", Howe used the film to claim the mutilations were linked to UFOs and aliens.

[120] Mirage Men discusess how, on April 20, 1979, U.S. Attorney R. E. Thompson and US Senator Harrison Schmidt held a public meeting about the ongoing cattle mutilations.

After attempting to barricade himself in his home using sandbags, his family admitted him to the mental health unit of Presbyterian Anna Kaseman Hospital; He remained under observation there for one month.

[133][additional citation(s) needed] The 1977 British television mockumentary Alternative 3 linked mutilations to a fictional plan to transport livestock to secret military bases on the Moon and Mars.

[134][additional citation(s) needed] The 1992 film Sneakers featured Dan Aykroyd as a conspiracy theorist who links aliens to cattle mutilations.

[138] The 1997 pilot episode of South Park titled Cartman Gets an Anal Probe references UFO and aliens as being linked to cattle mutilation.