Melvyn is a 6 1/2 year old Boston Terrier surrendered with his littermate sister after they became aggressive towards the owner's other Boston Terriers triggered by the doorbell.    They also attacked a visiting chihuahua puppy. Melvyn and his sister have been separated.  Melvyn is very affectionate but we think he will do best in an only dog home.  Melvyn is up to date on his vaccines and microchipped.