9 Granulomatous meningoencephalitis
Looking in one direction for an extended period of time is often a sign of cerebral disease. Staring at walls, into corners, or ‘into space’ are common presenting signs and distracting the animal may or may not be successful at stopping it. Neck pain limits head movement and general activity but such animals move their eyes towards stimuli and are mentally responsive. Recently-blind animals move slowly, bump into objects and do not respond to visual clues; clinical diagnosis is straightforward.
Hour-long episodes of being mentally unresponsive while lying on the sofa and staring at the wall commenced 6 months prior to referral. The events occurred at least once a week at any time of day and only when indoors. The dog was normal between the events. No other abnormalities were reported.
It may not have been neurological: the dog may have had undiagnosed arthropathy causing a reluctance to move but this was not evident in the history or physical examination. An age-related hearing loss may not have been noticed previously and have contributed to the dog’s lack of response to being called. A trial of non-steroidal anti-inflammatory drugs (NSAIDs) had been used but this had had no effect on the frequency or duration of the events and had been discontinued.
Cognitive dysfunction syndrome, a progressive, incurable loss of normal behaviour in the absence of any other known cause, was a consideration in this aged dog. Owners often describe their pet as ‘senile’. Systemic or primary neurological diseases must be ruled out first before diagnosing this condition.