title: Developmental and behavioral effects of toe clipping on neonatal and preweanling mice with and without vapocoolant anesthesia.
abstract: Toe clipping is used to identify and genotype preweanling mice, but the procedure generates concerns relevant to pain and distress. The few pertinent studies available evaluated mice between postnatal days (PND) 3 and 7, advocate the use of toe clipping in mice PND 7 or younger, and identify handling as the most distressing aspect of the procedure. Because both toe and tail clipping may be necessary in older mice to obtain sufficient DNA for genotyping, we surmised that performing these procedures concurrently to minimize handling would be beneficial. We also examined reflex development until PND 21 and adult behavior at 8 to 10 wk of age in mice toe clipped at PND 7 or 17 and the benefits of using topical vapocoolant anesthesia. C57BL/6J pups at PND 7 and 17 were assigned to 1 of 4 groups: 1) clipping of digit 3 of contralateral fore- and hindpaws; 2) toe clipping after topical vapocoolant anesthesia; 3) unclipped, unsprayed controls; and, 4) unclipped and vapocoolant-sprayed. Compared with unanesthetized pups, those sprayed with vapocoolant vocalized and struggled more when handled and had more bleeding, erythema, and swelling, which persisted for as long as 12 h after toe clipping. Reflex development, anxiety, locomotion, and motor coordination were not different among groups or with regard to the age of toe clipping. No tissue reaction was noted microscopically in paws collected at 10 wk of age. We conclude that the use of vapocoolant cannot be recommended due to its harmful effects and that toe clipping at PND 7 or 17 does not significantly affect the long-term welfare of mice.
authors.affiliation: Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan-Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University, The University of Melbourne, Melbourne, Australia. lee-ronn.paluch@unimelb.edu.au.
authors.forename: Lee-Ronn
authors.initials: LR
authors.lastname: Paluch
authors.affiliation: Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan-Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University.
authors.forename: Christine C
authors.initials: CC
authors.lastname: Lieggi
authors.affiliation: Weill Cornell Medical College, New York, New York.
authors.forename: Magali
authors.initials: M
authors.lastname: Dumont
authors.affiliation: Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan-Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Monette
authors.affiliation: Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Elyn R
authors.initials: ER
authors.lastname: Riedel
authors.affiliation: Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan-Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University.
authors.forename: Neil S
authors.initials: NS
authors.lastname: Lipman
mesh_terms: D000758:Anesthesia / Q000662:veterinary; D000822:Animal Husbandry / Q000379:methods*; D000823:Animal Identification Systems / Q000379:methods; D000818:Animals; D000830:Animals, Laboratory; D000831:Animals, Newborn; D001522:Behavior, Animal; D005260:Female; D005838:Genotype; D006234:Handling, Psychological; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010146:Pain / Q000662:veterinary; D011897:Random Allocation; D014034:Toes / Q000601:surgery*