Police say the Westfield boy was taken to a Westfield hospital after being bitten Tuesday afternoon, then was transported to a Springfield hospital for additional surgery in an attempt to save the arm, which suffered damage to the brachial artery.
Animal control officer Kenneth Frazer says the boy's parents told him that doctors are not sure the arm can be saved.
The Westfield News ( http://bit.ly/12kLt1N) reports that the boy was bitten on the upper arm as he was letting the 3-year-old American bulldog in the house.
The boy's father said the dog has "territorial issues" and asked that it be removed from his home and euthanized.
No names were released.
Information from: The Westfield (Mass.) News, http://thewestfieldnews.com