The Sleep of Shelter Dogs Was Not Disrupted by Overnight Light Rather than Darkness in a Crossover Trial

Abstract

Simple SummaryDogs are often left unattended overnight in shelters. This has led shelter mangers to worry that the dogs were suffering from separation anxiety and, therefore, exhibiting stereotypic or repetitive behaviors such as pacing, barking or digging at exits. Mangers also worried that dogs exposed to light at night were not able to sleep or slept less because some areas of the shelter were lit for security reasons. The ten dogs in this study were walked twice daily and provided with many enrichment devices and music during the day. They were housed in individual rooms each with a window allowing visualization of the dog by the public and vice versa. The dogs slept 10.8 h/night when in darkness and 10.5 h/night when their pens were lightened; there was no significant difference. They exhibited no stereotypic behaviors. They slept in bouts of slightly less than an hour, arising after each bout to stand up and then lie down again. Apparently, these well-stimulated shelter dogs slept soundly in the absence of people.AbstractDogs in shelters may be unattended at night. The purpose of this study is to describe the night-time behavior of dogs in a shelter and to determine if artificial light affected their sleeping patterns. Ten dogs were video-recorded under both light and dark conditions and their behavior recorded using focal animal sampling. The dogs were lying down 649 ± 40 min (mean ± SD) in the light condition and 629 ± 58 min in the dark condition each night. They awoke, stood up, turned around and then lay down again every 48 to 50 min. There was no significant difference in time spent lying between the two conditions (p > 0.05). Light did not seem to affect their behavior. The conclusion is that dogs in shelters may sleep in the absence of people and that light does not disrupt their sleep patterns.

Beyond Lux: Methods for Species and Photoreceptor-Specific Quantification of Ambient Light for Mammals

“…Furthermore, given the significant land and energy usage required for farm animal operations, the identification of optimum lighting conditions that balance productivity, health, and electricity usage has the potential to generate substantial energy savings (51)(52)(53). Additionally, the impact of evening and night-time light exposure in the home environment on human sleep is well-documented( 54), but remains unknown for pets (55). One process that could facilitate these applications would be simplification of the 4 -opic quantities required to fully describe irradiance for most mammalian species to a single metric that provides a reasonable prediction of light responses of interest under most circumstances.…”

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

“…Similarly, Houpt et al (2019) investigated the behaviour (i.e. sleep behaviour, bout length and bout number and the number of turns and walking) of 10 sheltered dogs (six females and four males, aged from 6 months to 7 years) exposed or not to light during the night, aiming to describe the night-time behaviour of dogs and the influence of artificial light.…”

“…illuminance and time schedule) are reported in different scientific studies investigating dogs' physiology (Siwak et al, 2003;Refinetti and Piccione, 2005;Bertolucci et al, 2008;Piccione et al, 2008;Piccione et al, 2009;Piccione et al, 2010;Giannetto et al, 2014) and behaviour (i.e. sleep patterns) (Fukuzawa and Nakazato, 2015;Houpt et al, 2019).…”

“…The behaviour of dogs exposed to light during the night was compared with that of dogs not exposed to light. No difference was found in the sleeping behaviour between the group in the dark and the group in the light (Houpt et al., 2019 ); however, the authors acknowledged the limitations of the small sample size and the lack of intra‐observer accuracy tests.…”

Nocturnal activity as a useful indicator of adaptability of dogs in an animal shelter and after subsequent adoption

“…Dogs in an animal shelter spent 45% of their time asleep over a period of 24 h, and 72% of the night-time (17:00–08:00) 23 . Another study found sheltered dogs to lie with their head down for around 87–90% during the night (19:00–07:00) 24 . Elderly dogs (8–13 years) did not sleep between 14:00 and 16:00 on the first day in the shelter, but on day 6 they spent 43% of this timeslot asleep 25 .…”