SLEEP, WORK, AND THE EFFECTS OF SHIFT WORK IN DRUG DETECTOR DOGS CANIS-FAMILIARIS

Sleep-wake cycles of six drug detector dogs were video recorded, and t he effects on them of shift work assessed. Observations were also reco rded of interactions between dogs and their handlers during rest and w ork. Non-working dogs recorded immediately after work or at the same t ime of day or night when not scheduled for work, slept for 43 +/- 16% (SD) of the 8-h recording sessions. They had 3.8 +/- 1.2 sleep session s per h, each of which lasted 7.2 +/- 2.3 min. Active sleep occurred d uring 6.4% +/- 4.8% of the total recorded time; there were 0.6 +/- 0.4 active sleep sessions per h, each lasting on average 5.9 +/- 3.8 min. The rhythms, duration and nature of active sleep were closely compara ble with rapid eye movement (REM) sleep patterns recorded electrophysi ologically by other workers; active and REM sleep in dogs are most pro bably identical. Patterns of sleep-wake cycles were not altered when h andler-dog teams worked different day and night shifts. The ability of dogs to cope with changing shifts may be due to their natural brief a nd frequent sleep-wake cycles which may allow them sufficient and easy adjustment to changing routines. Two dogs examined after extended per iods of not working showed a first-day-back-at-work effect in which ac tive sleep on the following night was diminished, and less total time was spent asleep.