Rage Syndrome, also known as Sudden Onset Aggression or (SOA) or Avalanche of Rage Syndrome, is a rare but serious behavioral problem that has been reported most commonly in the English Springer Spaniel but also in a variety of other dog breeds.

While I have not seen or experienced this personally I wanted to reply because I have found that it does affect the Bull Terrier.  Would be interesting to read what others think.