Rodent housing

Improved diagnostic capabilities and a desire to reduce or refine the use of animals as soiled bedding sentinels (SBS) have driven interest in developing the use of PCR-based testing methods, such as exhaust dust testing (EDT), for routine rodent health surveillance. We compared the absolute and quantitative PCR results from EDT filters with SBS mice by routine screening via a panel of 19 infectious agents including agents known to be excluded or present in the colony. In this study, EDT and SBS were compared at days 0, 90, and 180 in 3 facilities ( n = 12 rooms) with animals housed on IVC racks ( n = 19 double-sided and 23 single-sided racks)...

In rodents, the first weeks of postnatal life feature remarkable changes in fear memory acquisition, retention, extinction, and discrimination. Early development is also marked by profound changes in brain circuits underlying fear memory processing, with heightened sensitivity to environmental influences and stress, providing a powerful model to study the intersection between brain structure, function, and the impacts of stress. Nevertheless, difficulties related to breeding and housing young rodents, preweaning manipulations, and potential increased variability within that population pose considerable challenges to developmental fear research...

Scrub typhus is a re-emerging disease caused by Orientia tsutsugamushi , transmitted by mites belonging to the family Trombiculidae . Humans and rodents acquire the infection by the bite of larval mites/chiggers. Suncus murinus , the Asian house shrew, has been reported to harbor the vector mites and has been naturally infected with O. tsutsugamushi . The present study aimed to localize and record O. tsutsugamushi in the tissues and the host response in shrews naturally infected with O. tsutsugamushi . Sheehan's modified May-Grunwald Giemsa staining was carried out in 365 tissues from 87 animals, and rickettsiae were documented in 87 tissues from 20 animals...

Synanthropic rodents play a crucial role in maintaining the life cycle of Toxoplasma gondii in anthropized regions and can serve as indicators of environmental oocyst contamination. This investigation aimed to explore the occurrence of T. gondii infection within synanthropic rodent populations using a molecular diagnostic technique targeting the 18S rDNA gene, which is generic for Coccidia, with subsequent specific PCR confirmation. We examined 97 brown rats ( Rattus norvegicus ), 67 black rats ( R. rattus ), 47 house mice ( Mus musculus ), and 1 common shrew ( Sorex araneus )...

Rodents are sensitive to the emotional state of conspecifics. While the presence of affiliative social partners mitigates the physiological response to stressors (buffering), the partners of stressed individuals show behavioral and endocrine changes indicating that stress parameters can be transmitted across the group members (contagion). In this study, we investigated the social contagion/buffering phenomena in behavior and neuroendocrine mechanisms after exposure to chronic stress, in groups of rats living in the PhenoWorld (PhW)...

Robertsonian chromosomes form by fusion of two chromosomes that have centromeres located near their ends, known as acrocentric or telocentric chromosomes. This fusion creates a new metacentric chromosome and is a major mechanism of karyotype evolution and speciation. Robertsonian chromosomes are common in nature and were first described in grasshoppers by the zoologist W. R. B. Robertson more than 100 years ago. They have since been observed in many species, including catfish, sheep, butterflies, bats, bovids, rodents and humans, and are the most common chromosomal change in mammals...

INTRODUCTION: Depression is a human mental disorder that can also be inferred in non-human animals. This study explored whether time spent inactive but awake ("IBA") in the home-cage in mice was further triggered by risk factors similar to those increasing vulnerability to depression in humans (early life stress, genetic predispositions, adulthood stress). METHODS: Eighteen DBA/2 J and 18 C57BL/6 J females were tested, of which half underwent as pups a daily maternal separation on post-natal days 2-14 (early-life stress "ELS") (other half left undisturbed)...

The Natal multimammate mouse ( Mastomys natalensis ) is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10-30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village...

BACKGROUND: Claudin 18.2 (CLDN18.2) is a highly anticipated target for solid tumor therapy, especially in advanced gastric carcinoma and pancreatic carcinoma. The T cell engager targeting CLDN18.2 represents a compelling strategy for enhancing anti-cancer efficacy. METHODS: Based on the in-house screened anti-CLDN18.2 VHH, we have developed a novel tri-specific T cell engager targeting CLDN18.2 for gastric and pancreatic cancer immunotherapy. This tri-specific antibody was designed with binding to CLDN18...

This review article delves into the details of the 3R-Refinement principles as a vital framework for ethically sound rodent research laboratory. It highlights the core objective of the refinement protocol, namely, to enhance the well-being of laboratory animals while simultaneously improving the scientific validity of research outcomes. Through an exploration of key components of the refinement principles, the article outlines how these ethics should be implemented at various stages of animal experiments. It emphasizes the significance of enriched housing environments that reduce stress and encourage natural behaviors, non-restraint methods in handling and training, refined dosing and sampling techniques that prioritize animal comfort, the critical role of optimal pain management and the importance of regular animal welfare assessment in maintaining the rodents well-being...

The ferret (Mustela putorius furo) is a small domesticated species of the family Mustelidae within the order Carnivora. The present article reviews and discusses the current state of knowledge about housing, care, breeding, and biomedical uses of ferrets. The management and breeding procedures of ferrets resemble those used for other carnivores. Understanding its behavior helps in the use of environmental enrichment and social housing, which promote behaviors typical of the species. Ferrets have been used in research since the beginning of the twentieth century...

INTRODUCTION: The gray short-tailed opossum, Monodelhis domestica (M. domestica) is a widely used marsupial model species that presents unique advantages for neurodevelopmental studies. Notably their extremely altricial birth allows manipulation of postnatal pups at timepoints equivalent to embryonic stages of placental mammals. A robust literature exists on the development of short-tailed opossums, but many researchers working in the more conventional model species of mice and rats may find it daunting to identify the appropriate age at which to conduct experiments...

PURPOSE: Rodents are one of the most abundant and diverse species of mammals and have recently been identified as carriers of numerous human pathogens. The current study was conducted to assess the prevalence, subtype (STs) distribution, and zoonotic potential of Blastocystis spp. in various species of rodents in Shiraz, southwestern Iran. METHODS: For this aim, a total of 120 fresh fecal samples were collected from Mus musculus (n = 40), Rattus norvegicus (n = 40), and Rattus rattus (n = 40) in various municipality districts of Shiraz (6 out of 10 districts) between February and November 2020...

Cutaneous leishmaniasis is of particular importance in southern Iran. This study aimed to investigate the infection of rodents with Leishmania major in an urban area of Fars Province, located in southern Iran. Rodents were trapped and samples from the liver, spleen, and skin were collected. Impression smears were prepared from these tissues and any skin lesions and were examined microscopically. In addition, a portion of the samples were preserved for subsequent DNA extraction. A total of 41 rodents belonging to three species were caught from 10 trapping stations in gardens or houses within the area...

Neuroscience heavily relies on animal welfare in laboratory rodents as it can significantly affect brain development, cognitive function and memory formation. Unfortunately, laboratory animals are often raised in artificial environments devoid of physical and social stimuli, potentially leading to biased outcomes in behavioural assays. To assess this effect, we examined the impact of social and physical cage enrichment on various forms of motor coordination. Our findings indicate that while enriched-housed animals did not exhibit faster learning in eyeblink conditioning, the peak timing of their conditioned responses was slightly, but significantly, improved...

The world is facing a major pulse of ecological and social changes that may favor the risk of zoonotic outbreaks. Such risk facilitation may occur through the modification of the host's community diversity and structure, leading to an increase in pathogen reservoirs and the contact rate between these reservoirs and humans. Here, we examined whether anthropization alters the relative abundance and richness of zoonotic reservoir and non-reservoir rodents in three Socio-Ecological Systems. We hypothesized that anthropization increases the relative abundance and richness of rodent reservoirs while decreasing non-reservoir species...

Nesting is a normal, evolutionary conserved rodent behavioural phenotype that is expressed for purposes of breeding, safety, and thermal regulation. Further, nesting is commonly assessed as marker of overall rodent health and wellbeing, with poorer nesting performance generally proposed to resemble a worse state of health. Deer mice can be bidirectionally separated with 30% of mice presenting with excessively large nesting behaviour (LNB). All laboratory-housed deer mice are exposed to identical environmental conditions...

In the Azores, complaints about grape loss to birds have become recurrent. Although winegrowers frequently blame the endemic Azores Woodpigeon Columba palumbus azorica, data about the magnitude of grape damage and the species responsible for them are lacking. This study provides detailed information about grape damage caused by vertebrates on Pico Island, home to the main wine-growing area of the region. Vineyards were monitored during the ripening period in 2017 and 2018. Damage was assessed by determining the number of plucked, pecked and bitten grapes for a total of 850 bunches...

The search for alternatives to live animal sentinels in rodent health monitoring programs is fundamental to the 3Rs (Reduction, Replacement, and Refinement) of animal research. We evaluated the efficacy of a novel battery-operated tumbler device that rotates soiled bedding in direct contact with sample media against the use of exhaust sample media and soiled bedding sentinel (SBS) mice. Four rodent racks were used, each with 3 test cages: a cage with a tumbler device that rotated for 10 min twice a week (TUM10), a cage with a tumbler device that rotated for 60 min twice a week (TUM60), and a cage housing 2 female Crl:CD1(ICR) mice...

BACKGROUND: Stress-induced illnesses, like major depression, are among the leading causes of disability across the world. Consequently, there is a dire need for the validation of translationally-suited animal models incorporating social stress to uncover the etiology of depression. Prairie voles (Microtus ochrogaster) are more translationally relevant than many other rodent models as they display monogamous social and bi-parental behaviors. Therefore, we evaluated whether a novel social defeat stress (SDS) model in male prairie voles induces depression-relevant behavioral outcomes...