Roger Mundell Jr. said the bobcat hissed then leaped about eight feet and pounced on him after he entered the garage in Brookfield, a town about an hour outside of Boston where bobcats are occasionally spotted but rarely attack people.
The animal, believed to be rabid, bit Mundell repeatedly on the face and scratched his shoulders during Sunday's attack. Mundell was eventually able to free himself by removing his jacket, he said.
Mundell then ran out of the garage, shutting a door behind him, but the cat escaped through another partially opened door and confronted his wife and 15-year-old nephew, who were outside, Mundell said.
The bobcat bit the nephew on the forearm until Mundell pulled the animal off him and they pinned it to the ground, beating it with a metal crutch. Mundell's wife then got a pistol from the house and they shot it.
"I was bleeding all over the place," said Mundell, 53, who works for a paving company. "It wanted us bad. It obviously was rabid."
He said he was bitten and scratched at least 30 times, and that he and his nephew had begun treatment for rabies at a hospital on Sunday. His wife was also treated because she came into contact with the animal's blood, though she was not bitten.
Officials were testing the bobcat for the disease, but Mundell said he assumed from its behaviour that it was rabid.
"Usually a bobcat will stay away from you," he said.
(Editing By Barbara Goldberg and Nick Zieminski)