When Macho B's decline became apparent, some researchers began to wonder whether the country's only known wild jaguar had something called "capture myopathy."
The sometimes-fatal disorder can occur, as the name implies, when animals are captured. The combination of stress, fear and exertion damages muscle tissue and can harm organs.
"Department personnel suspected capture myopathy/renal failure," U.S. Fish and Wildlife Service spokesman Jeff Humphrey wrote in a briefing document prepared for the service's regional director and obtained by the Star through a public-records request.
But the sort of necropsy performed by veterinarians at the Phoenix Zoo did not provide enough information to determine whether he had the disorder, two outside veterinarians said.
Some elements of Macho B's case suggest capture myopathy may have occurred. The necropsy report indicated some muscles had atrophied, which can be a sign of myopathy.
Also, Macho B's paw that was caught in the snare was quite swollen, and if that prevented the jaguar from going after food or water, it would be considered a form of capture myopathy.
In a statement released on Friday, Game and Fish noted that a written account of the Feb. 18 capture said the jaguar "didn't limp as he left."
The author of that account, Game and Fish wildlife technician and biologist Thorry Smith, said snared cougars seldom move more than a fraction of a mile for a day or more on swollen, snared feet. But Macho B traveled three miles in the first three hours of his capture.
He slowed after that, however — particularly in his last few days in the wild. He was recaptured shortly after noon on March 2 only five miles from the original capture site and euthanized late that afternoon. Still, satellite tracking data indicate that the jaguar was close to water throughout his final 12 days and made frequent visits to water sources, Game and Fish's statement said.
At a press briefing on March 6, a Phoenix Zoo veterinarian said capture myopathy wasn't a factor in the illness that led the zoo to euthanize Macho B.
"Capture myopathy in the zoo world is a daily event, especially in hoof stock like antelopes and some of these fragile little guys. It does not cause renal failure. This cat had renal failure. Capture myopathy is an acute syndrome, a deadly syndrome. That was not the case here," said Dean Rice, the zoo's executive vice president and head veterinarian.
It's true that capture myopathy is not as common among predators such as jaguars, as prey species, said David Jessup, senior wildlife veterinarian for California Fish and Game.
"Mountain lions and bobcats who are caught in snares most of the time will struggle for a few minutes, then will hunker down and wait," Jessup said. "It's very uncommon for them to panic for a prolonged period of time."
But myopathy could come into play if a captured cat struggled for long in the snare, Jessup said.
When Arizona Game and Fish employees arrived at the site of Macho B's capture Feb. 18, the cat was in a "quiet state," wildlife technician Thorry Smith reported.
But that was probably not the case throughout his capture, which Game and Fish estimates lasted between three and 14 hours. The tree where Macho B was trapped was covered with dozens of deep scratches last week, up to a height of about seven feet. Roots within about eight feet of the tree also showed deep scratches.
But even those scratches are not enough evidence to show that the jaguar's struggle could have caused myopathy, leading to his death, Jessup said in an e-mail. And the fact that the broader site did not appear "torn up" suggests the jaguar did not make much of a struggle.