title: The time-to-integrate-to-nest test as an indicator of wellbeing in laboratory mice.
abstract: Minimizing and alleviating pain and distress in laboratory mice without compromising the methodologic integrity of research is a crucial goal. However, current methods for welfare assessment in mice are not well suited to cageside checks. In the present study, we developed a simple assessment tool-the time-to-integrate-to-nest test (TINT)-and evaluated its ability to identify mice with compromised welfare. To conduct the TINT, a nominal amount of nesting material is added to a mouse cage, and the nesting behaviors that occur immediately thereafter are observed. The TINT yields a positive result when a mouse integrates the new nesting material into the main nest site within 10 min; failure to interact with the nesting material is defined as a negative TINT. Our first experiment examined whether genetic background and sex are associated with differences in the likelihood of a positive TINT in unmanipulated mice. A significant effect related to mouse strain was found: C3H/HeNCrl had the lowest positive TINT rate among the 10 strains evaluated. A second experiment assessed whether results of the TINT would be altered after a painful surgical procedure, such as carotid artery injury. Despite all mice having received buprenorphine as analgesia at the time of surgery, significantly more mice had a negative TINT for 2 d after surgery than before surgery. Based on the results of the current study, additional work is needed to specifically validate the TINT in injured and noninjured subjects.
authors.affiliation: Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA. meagan.rock@tufts.edu.
authors.forename: Meagan L
authors.initials: ML
authors.lastname: Rock
authors.affiliation: Department of Clinical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA.
authors.forename: Alicia Z
authors.initials: AZ
authors.lastname: Karas
authors.affiliation: Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA.
authors.forename: Katherine B Gartrell
authors.initials: KB
authors.lastname: Rodriguez
authors.affiliation: Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA.
authors.forename: Miranda S
authors.initials: MS
authors.lastname: Gallo
authors.affiliation: Charles River, Research Models and Services, Wilmington, Massachusetts, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Pritchett-Corning
authors.affiliation: Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Karas
authors.affiliation: Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Aronovitz
authors.affiliation: Charles River, Research Models and Services, Wilmington, Massachusetts, USA.
authors.forename: Brianna N
authors.initials: BN
authors.lastname: Gaskill
mesh_terms: D000818:Animals; D005260:Female; D006799:Housing, Animal; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009425:Nesting Behavior / Q000502:physiology*; D011897:Random Allocation; D013045:Species Specificity