BOSTON (CBS) – Hikers, dog walkers, and pet owners who frequent the Blue Hills Reservation are being warned that there may be rattlesnakes in the area.

Kymberlee O’Brien’s dog Bonnie was out on her usual walk in the Blue Hills last week, when the 6-year-old yellow lab stepped on a snake.

WBZ NewsRadio 1030′s Bernice Corpuz reports

The person walking Bonnie described the snake as big. It formed a two and a half foot-wide coil and the bite marks on Bonnie’s front left paw were an inch and a half apart.

“She looked like a truck had run over her,” said O’Brien. “She was just all black and blue.”

The dog was hospitalized for two days, but is now back home still limping a bit.

“She is not as prancy, and wiggly, but she wants to be,” says O’Brien.

She says no one knows for sure what kind of snake bit Bonnie, but park rangers suspect it was a timber rattle snake.