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Stress is an important factor that affects the welfare of mice used as research animals and therewith the reliability of research results. Currently the most common way of measuring stress levels is testing corticosterone levels from blood samples. However, taking these blood samples is invasive by itself and therefore a less invasive method thatis reliable is an improvement. Using infrared thermography to measure stress-induced hyperthermia could be such a non-invasive method. To use this method properly the different influences on the surface temperature of the body have to be explored. Previous research indicates that other factors may influence the surface temperature of animals. In this research the influence of different types of behavior on the eye and tail temperature of male C3H mice was explored. 16 male C3H mice were put in a testing cage for 30 minutes, for 5 consecutive days. The behaviors of the individual mice were logged continuously and the eye and tail temperature were measured using infrared thermography and were analyzed for every 5 minute interval. The different behaviors were divided into active and inactive behaviors, the duration of behavior of both groups were compared. Spearman’s correlation test was run to explore the correlation between the duration of each separate behavior and the two behavior groups and the tail and eye temperature of the mice. The results show a positive correlation between active behaviors and the eye temperature, and a negative correlation inactive behaviors and the eye temperature. The tail temperature the opposite was found; a positive correlation with the duration of inactive behaviors and a negative correlation with active behaviors. This shows that behavior and activity level is something to consider during research toward body temperature and eye and tail temperature. However, stress-induced hyperthermia was still measurable in the same data. This means that this method, if explored more thoroughly in the futu

Laboratory rats can experience acute stress during handling procedures, which can negatively affect animal welfare. The purpose of this research was to investigate if rats that had been regularly tickled or gentled from a young age experienced less acute stress during manual restraints due to the social buffer effect these procedures may provide. As read-out parameters for stress levels, maximum eye temperature and mid-tail temperature were used to reflect the stress-induced hyperthermia. Sixteen male Wistar rats (WU:Crl) with an age of three weeks at arrival in the lab were included in this study. Maximum eye temperature and mid-tail temperature were measured before, during and after a stressor period containing several manual restraints, using a FLIR T430sc thermal camera. Due to limitations, no reliable measurements were made for the eye temperature experiment and were, therefore, excluded from the results. For the mid-tail temperature, results showed that the gentled rats (G, n = 4) had a lower baseline tail temperature than the tickled rats (T, n = 8), where the control group (CONTROL, n = 4) showed the highest baseline temperature. During the stressor period, the tail temperatures of all rats dropped to a comparable lowest point temperature, suggesting repeated manual restraint is a stressful experience for all rats. Differences in temperature between the treatment groups during this period could not be distinguished, due to the differences in baseline temperature. Without additional parameters to assess stress levels and a behavioral study, no conclusions for this study could be made yet. However, future research may confirm the suggestion that tickling and especially gentling rats may positively affect animal welfare by improving the human-animal bond, lower the general fear of humans, decrease stress levels during manual restraints, and maybe lower chronic stress levels.

Training laboratory animals to voluntarily cooperate with husbandry and medical procedures can significantly reduce the level of stress these animals experience during these procedures. Habituation to humans and human handling is often a first step in training protocols. It is known in rabbits and rats that habituation to humans can reduce the fearfulness towards humans, which facilitates training. Currently, very little is known about behavioural habituation in guinea pigs. Thus, the objective of this explorative study was to see whether behavioural habituation towards human presence inside the cage could be observed in Dunkin Hartley guinea pigs. For this aim five Dunkin Hartley guinea pigs (used for educational purposes) were habituated to the presence of a human inside their cage over the course of three weeks. Daily habituation sessions were performed from Monday through Friday, where an observer was present inside the cage for 10-20 minutes. Behaviour shown during the first ten minutes of the first habituation session of the week were scored from video material using focal animal sampling. The behaviours scored were active locomotor behaviour, grooming behaviour, animal-human interaction, ingestive behaviour, comfort behaviour, the amount of time spent inside or outside shelter and other locomotor behaviour. The percentage of total time spent in a certain behaviour and the latency to first display a behaviour were used in the statistical analyses. The percentage of total time spent in ingestive behaviour was different between habituation sessions, but post-hoc analyses could not establish where the exact differences took place. No further significant statistical effects could be found. However, the percentage of total time spent underneath shelter and in other locomotive behaviour, as well as the latency to first leave shelter, showed a trend for a difference. This explorative study implies that behavioural habituation to the presence of a human inside the cag

The intraperitoneal (i.p.) injection in mice is a common, efficient and easy way to administer an animal a substance. Several restraining methods for this injection are in use. Various studies mention a frequency of misplacing an i.p. injection using a certain restraining method, however the frequency of misplacing an i.p. injection has never been compared between methods. To safely administer a substance through an i.p. injection, some form of restraint is necessary. The restraining itself causes a degree of stress in mice. However, the level of stress has never been determined when comparing different restraining methods. In the context of animal welfare and the 3R’s principle, it is relevant to determine which restraining method is most accurate and causes the least amount of stress. In this study frequency of misplacing the i.p. injection and the degree of stress, was determined comparing three restraining methods. Restraining the mouse head down (HD), restraining the mouse head up (HU) and using a method described by Baek et al.(2015)1 in which minimal restraint is required (BK). Accuracy was determined by administering a methylene solution intraperitoneally after which macroscopic pathology was conducted to determine the location. The acute stress reaction was measured by determining the level of blood plasma corticosterone (pCORT) and measuring eye, ear and tail temperature through infrared thermography (IRT). These parameters were measured after mice were restrained either HD, HU or BK (within group comparison, n=). Temperature of thermal images and level of corticosterone were compared between different restraining methods. Accuracy of the i.p. injection after all restraining methods was not significantly different, considering this all three restraining methods are equally valid to be used in practice. Corticosterone levels after HU restraint were significantly highest (HU n=18, HD n=19, BK n=18). However, this was not supported by the IRT data; temperatur

Item does not contain fulltext, Various protocols to induce chronic stress in rodents are being used to determine the effects and underlying mechanisms of prolonged stress experience. Recently, a novel chronic social stress (CSS) protocol has been developed for mice where social instability in adolescence and early adulthood is induced. This protocol has been shown to cause an increase in HPA-axis activity and acute avoidance behaviour in the elevated plus maze. The aim of the present study was to investigate the effect of this CSS protocol on habituation to an initially novel environment in CD1 mice, since it has been shown that initially high avoidance behaviour in mice can still be followed by rapid habituation, pointing towards an adaptive response. One group of male mice, the CSS group, was exposed to the CSS protocol for 7 weeks and we compared their behavioural and physiological responses with male mice that were housed in a stable social group, the SH group. The results reveal a decrease in body weight gain and fur condition, changes in adrenal weight and decreased GR mRNA expression in the CA1 and the dentate gyrus of the hippocampus in chronically stressed CD1 animals. Irrespective of such evidence for a significantly stressful effect of the protocol, CD 1 mice, after termination of the stress procedure, revealed habituation profiles that matched those of control animals. We conclude that the physiological and central-nervous effects caused by a CSS procedure as used in this experiment fall within the coping capacities of CD1 mice at the behavioural level.