A Farmingville woman is suing Riverhead after she was allegedly attacked by a pit bull she adopted at a town animal shelter.

Cassandra Cosgriff says her pit bull, Zen, attacked her inside her Farmingville home in February. Two years earlier, she adopted Zen from the Riverhead Town Animal Shelter. She says Zen had been a loving companion until the dog clamped on to her arm for 20 minutes.

Cosgriff says the attack caused nerve damage in her arm to the point where she couldn't move it. She says she has gone through multiple surgeries and physical therapy to get full movement back.

Cosgriff's lawsuit says that when she adopted the pit bull, workers at the Riverhead shelter never told her the dog had been abused and used in dogfighting. She's now suing the town for $5 million.

Cosgriff's attorney Sandra Radna says that she believes the shelter knew about the dog's history, but purposely withheld it.

"It doesn't matter the breed of the dog...any animal that has been this severely abused should not be placed with a family," says Cosgriff.

In a statement to News 12, Riverhead's attorney says "Pending a full investigation on our part to determine the accuracy of her statements, I want to hold off any real comment on the case."

The Riverhead Town Animal Shelter has since been taken over by the North Fork Animal Welfare League.