In the early 1980s the term “rage syndrome” was applied to serious uncharacteristic behavior in certain breeds of dogs including the English Springer Spaniel.
Rage syndrome is when the dog will develop a glazed look and attack people and/or other dogs without provocation. The rage episodes will last just a few seconds – the dog will be unaware of the rage and afterwards may return to a happy state, wagging its tail, etc.
There are no known neurological or behavioral symptoms.
The fact is, this rage syndrome is not just found in English Springer Spaniels, but happens in other breeds. Cocker Spaniels, for example, have been identified as another breed susceptible to this condition. Even then, it is a rare occurrence. Much of the research actually points to bad temperaments or other aggressive tendencies to be more common then rage syndrome.