Baseline sleep-wake patterns in the pointer dog.

The 24-hr electrographic patterns (EEG, EOG, EMG) of six normal pointer dogs were recorded in a laboratory setting. Two states of sleep (slow-wave and rapid eye movement) and wakefulness (alert and drowsy) were identified. The total recording period comprised 44% of alert wakefulness, 21% of the drowsy state, while slow-wave sleep occupied 23% and REM sleep 12% of the time. The mean length of a REM sleep episode averaged 6 min and the mean REM sleep cycle was 20 min. The mean polycyclic sleep-wake cycle was 83 min. Sleep episodes averaged 45 min and the mean waking episode was 38 min. There was an average of two REM sleep episodes per sleep-wake cycle. The dog has a propensity to sleep over a 16-hr interval from 1300 to 0500 but the most sleep occurred between 2100 and 0400 hr during darkness.