Laboratory rodent housing conditions vary significantly across laboratories and facilities. Variation in housing can be associated with animal stress leading to study variability and the subsequent inability to replicate experimental findings. Optimization and standardization of animal housing are...

Domesticated mice and rats have shown to be powerful model systems for biomedical research, but there are cases in which the biology of species is a poor match for the hypotheses under study. The California mouse (Peromyscus californicus) has unique traits that make it an ideal model for studying...

Minimum space allowances for laboratory rats are legislated based on weight and stocking rates, with the understanding that increased housing density encourages crowding stress. However, there is little evidence for these recommendations, especially when considering positive welfare outcomes. This...

The objective of this study was to compare cardiovascular function and home-cage behavior of male Sprague-Dawley rats under resting conditions or after common husbandry and experimental procedures when the animals were housed with 3 other rats in cages with 920 or 1250 cm² of floor space. Heart...

Maintaining compliance with cage density recommendations in The Guide for the Care and Use of Laboratory Animals precludes continuous trio breeding in standard-sized mouse cages. This study evaluated and compared several parameters of reproductive performance, intracage ammonia concentration, and...

Living together in large social communities within an enriched environment stimulates self-motivated activity in rats. We developed a modular housing system in which a single unit can accommodate as many as 48 rats and contains multiple functional areas. This rat colony cage further allowed us to...

205 rats were housed in cages in single-sex groups of 3, 5, 8 or alone for 8 weeks and behavioural observations were regularly made. Overall, females spent more time in escape-related behaviours than males. The number of rats per cage did not affect male time budgets in the long term but there were ...

The Guide for the Care and Use of Laboratory Animals (the Guide) recommends that terrestrial mammals be provided space free of urine and feces in which to rest. To evaluate the feasibility of meeting this recommendation, the author examined the availability of feces-free resting areas in standard...

In social animals, recovery from the adverse effects of distressing stimuli is promoted by subsequent cohousing with a conspecific animal(s). This phenomenon has been termed housing-type social buffering. We previously found that social housing induced housing-type social buffering in...

Environmental enrichment provides physiological and emotional benefits to laboratory rodents. Red tinted shelters are a common enrichment found in laboratories that provide rodents with a hiding space shielded from bright light. Red tinting alters the light's spectral make-up which reduces the...