An interesting article entitled “Effect of multilevel laboratory rat caging system on the well-being of the singly-housed Sprague Dawley rat” from the Laboratory Animal Resource Center, School of Medicine, Indiana University, was published on August 12, 2014, on Laboratory animal Online.
The article emphasizes the importance, as good husbandry practices, to allow animals to engage in species appropriate postural adjustments without touching the enclosure walls.
The study, described in the article, evaluated the well-being of rats housed in the Double Decker Cage, manufactured by Tecniplast. The evaluation methodologies included assessment of behavioral observations in the home cage, physiological assessment of metabolism and immune functions and determination of the affective state using a spatial cognitive bias assay.
The results of this study suggest that the use of a multilevel caging system (Double Decker Cages) that provides rats with more space and complexity structure may improve the well-being of rats that are used in research.
Indeed, the conclusions of the study are that the provision of access to all levels of a multilevel caging system induced a positive affective state in rats.
Rats that were chronically housed with full access to the multilevel caging system (Double Decker cage) demonstrated a reduction in their neurotrophil/lymphocyte ration, suggesting an improvement in their overall well-being.