In Iran, an international team of scientists found the cats had turned to hunting domestic animals because numbers of their usual prey such as gazelle, wild sheep and goats had been reduced by poachers, the BBC reported Wednesday.
It had been thought the Asiatic cheetah might survive by eating more rodents and hares in areas where their normal prey had declined, but this was found to be not true, researchers said.
"The hare or the rabbit... (are] a very important part of their diet. But that's such a hard thing to catch for so little that it's not sustainable," said Laurie Marker, founder of the Cheetah Conservation Fund in Namibia, who collaborated on the Iranian study.
The survival of the cats may be dependent of efforts to clamp down on poaching, researchers said.
"We need to have the small and medium-sized antelope," Marker said.
The current estimate is that there are only 70 Asiatic cheetahs left in the wild, all of them in Iran, she said.