Give Them a Toy or Increase Time out of Kennel at Lawn Areas: What Is the Influence of These Interventions on Police Dogs' Welfare?

Simple Summary

Poor environments such as kennels can lead to compromised welfare, as they usually lack many kinds of stimuli. Working dogs are not only kept in kennels, but they are also often housed without any kind of environmental enrichment, allegedly due to motivational reasons, which is conducive to all kinds of behavioural issues. Thus, this study aimed to evaluate the impact of two interventions, a toy and going out to a lawn area, on a group of police dogs. Behavioural and physiological data were used to evaluate the animals’ responses to treatments. We identified a large variety of behavioural profiles amongst the animals that presented different levels of stereotypies, which is an abnormal behaviour pattern that can be associated with stress. A tendency to a reduction in these behaviours in high-stereotyping individuals was observed after dogs were able to go to the lawn area, indicating beneficial effects of this intervention. The physiological data indicated that the cumulative effect of interventions can also have a beneficial impact and that environmental enrichment plays an important role in kennelled police dogs’ welfare.

Abstract

This work was aimed at identifying the effectiveness of two interventions applied to a group of eight kennelled police dogs. Interventions consisted of access to a lawn area (350 m²) and “toy” (a 30 cm jute rag roll, hanging from the kennel ceiling), both available for 15 min a day, for four days in a row. We collected behavioural data and faecal samples for cortisol metabolites evaluation before, during and after interventions. Faecal cortisol metabolites levels were significantly reduced (Friedman, X2(3) = 12.450; p = 0.006) during the second round of intervention, regardless of the type of intervention, indicating that the interventions can have a beneficial cumulative effect. Regarding the frequency of stereotyped behaviour, cluster analysis identified two groups of individuals: (1) high-stereotyping individuals (n = 3) that had a tendency to reduce stereotyping behaviours in the lawn intervention when compared to toy intervention (Friedman, X2(3) = 2.530; p = 0.068), and (2) low-stereotyping animals (n = 5) that did not present significant behavioural changes during the experiment. The variety of behavioural and endocrine parameters evaluated highlights the need to account for the individual in behaviour and welfare research. Overall, our results suggest that even simple environmental enrichment can be an effective method to mitigate behaviour and physiological signs of stress.

Brain Circuit of Claustrophobia-like Behavior in Mice Identified by Upstream Tracing of Sighing

Emotions are distinct patterns of behavioral and physiological responses triggered by stimuli that induce different brain states. Elucidating the circuits is difficult because of challenges in interrogating emotional brain states and their complex outputs. Here, we leverage the recent discovery in mice of a neural circuit for sighing, a simple, quantifiable output of various emotions. We show that mouse confinement triggers sighing, and this "claustrophobic" sighing, but not accompanying tachypnea, requires the same medullary neuromedin B (Nmb)-expressing neurons as physiological sighing. Retrograde tracing from the Nmb neurons identified 12 forebrain centers providing presynaptic input, including hypocretin (Hcrt)-expressing lateral hypothalamic neurons. Confinement activates Hcrt neurons, and optogenetic activation induces sighing and tachypnea whereas pharmacologic inhibition suppresses both responses. The effect on sighing is mediated by HCRT directly on Nmbneurons. We propose that this HCRT-NMB neuropeptide relay circuit mediates claustrophobic sighing and that activated Hcrt neurons are a claustrophobia brain state that directly controls claustrophobic outputs.

Influence of experimental set-up and methodology for measurements of metabolic rates and critical swimming speed in Atlantic salmon Salmo salar

In this study, swim-tunnel respirometry was performed on Atlantic salmon Salmo salar post-smolts in a 90 l respirometer on individuals and compared with groups or individuals of similar sizes tested in a 1905 l respirometer, to determine if differences between set-ups and protocols exist. Standard metabolic rate (SMR) derived from the lowest oxygen uptake rate cycles over a 20 h period was statistically similar to SMR derived from back extrapolating to zero swim speed. However, maximum metabolic rate (MMR) estimates varied significantly between swimming at maximum speed, following an exhaustive chase protocol and during confinement stress. Most notably, the mean (±SE) MMR was 511 ± 15 mg O₂ kg^-1 h^-1 in the swim test which was 52% higher compared with 337 ± 9 mg O₂ kg^-1 in the chase protocol, showing that the latter approach causes a substantial underestimation. Performing group respirometry in the larger swim tunnel provided statistically similar estimates of SMR and MMR as for individual fish tested in the smaller tunnel. While we hypothesised a larger swim section and swimming in groups would improve swimming performance, U_crit was statistically similar between both set-ups and statistically similar between swimming alone v. swimming in groups in the larger set-up, suggesting that this species does not benefit hydrodynamically from swimming in a school in these conditions. Different methods and set-ups have their own respective limitations and advantages depending on the questions being addressed, the time available, the number of replicates required and if supplementary samplings such as blood or gill tissues are needed. Hence, method choice should be carefully considered when planning experiments and when comparing previous studies.

Sea bass Dicentrarchus labrax (L.) bacterial infection and confinement stress acts on F-type lectin (DlFBL) serum modulation

The F-lectin, a fucose-binding protein found from invertebrates to ectothermic vertebrates, is the last lectin family to be discovered. Here, we describe effects of two different types of stressors, bacterial infection and confinement stress, on the modulation of European sea bass Dicentrarchus labrax (L.) F-lectin (DlFBL), a well-characterized serum opsonin, using a specific antibody. The infection of the Vibrio alginolyticus bacterial strain increased the total haemagglutinating activity during the 16-day testing period. The DlFBL value showed an upward regulation on the first, second and last days and underwent a slight downward regulation 4 days post-challenge. In contrast, the effect of confinement and density stress showed a decrease in the plasma concentration of lectin, ranging from 50% to 60% compared with the control. The modulation of DlFBL is in line with the hypothesis that humoral lectins could be involved and recruited in the initial recognition step of the inflammation, which leads to agglutination, and the activation of mechanisms responsible for killing of the pathogens.

Behaviour, physiology and carotenoid pigmentation in Arctic charr Salvelinus alpinus

The behaviour during an exploration task and the response to a confinement stress of Arctic charr Salvelinus alpinus were evaluated. Behaviour of individuals during 90 min of exploration was classified into high and low activity. High-activity individuals had higher plasma cortisol levels following stress compared to low-activity individuals. This indicates that high- and low-activity individuals correspond to reactive and proactive stress-coping styles. Further, a pigmentation analysis showed that high-activity individuals had a higher number of carotenoid spots cm⁻² than low-activity individuals. Thus, carotenoid pigmentation, as melanin pigmentation in other salmonids, could be linked to stress-coping style in S. alpinus.