Sorry to hear about this. I've never heard of this type of dog. Are they vicious in general towards other animals?
From Wikipedia: http://en.wikipedia.org/wiki/Chesapeake_Bay_Retriever
The Chesapeake Bay Retriever is valued for its bright and happy disposition, intelligence, quiet good sense, and affectionate protective nature. Some of them can be quite vocal when happy, and some will 'smile' by baring their front teeth in a peculiar grin - this is not a threat but a sign of joy or submissiveness.
Like other dogs, Chesapeake Bay Retrievers can make excellent family dogs when socialized properly. Chesapeakes can be more assertive and willful and may be reserved with strangers while others are passive and outgoing with people. It simply depends on the personality of the dog.
Photo Credit: http://www.wetnosespetphotography

