A 3-year-old boy was listed in fair condition Sunday night following surgery for injuries suffered when he was trampled by a bull moose that had wandered into his family's yard, authorities said.

Josh Terry, son of Val and Nora Terry, startled a moose after he stepped from his house at 3:30 p.m. on Saturday, the Fremont County Sheriff's Office reported.The boy's father chased the moose away. The boy was taken to Madison Memorial Hospital in Rexburg and was transferred to Eastern Idaho Regional Medical Center in Idaho Falls, where he underwent surgery for liver injuries, a hospital spokeswoman said.

The Sheriff's Office said deputies and Idaho Fish and Game Department game wardens found the moose, but when they tried to tranquilize it to move it out of the area, the animal died.

Authorities warned that moose can be "extremely dangerous," and local law enforcement agencies and Fish and Game should be notified if they pose a potential problem.