Classification and reporting of severity experienced by animals used in scientific procedures: FELASA/ECLAM/ESLAV Working Group report.

Directive 2010/63/EU introduced requirements for the classification of the severity of procedures to be applied during the project authorisation process to use animals in scientific procedures and also to report actual severity experienced by each animal used in such procedures. These requirements offer opportunities during the design, conduct and reporting of procedures to consider the adverse effects of procedures and how these can be reduced to minimize the welfare consequences for the animals. Better recording and reporting of adverse effects should also help in highlighting priorities for refinement of future similar procedures and benchmarking good practice. Reporting of actual severity should help inform the public of the relative severity of different areas of scientific research and, over time, may show trends regarding refinement. Consistency of assignment of severity categories across Member States is a key requirement, particularly if re-use is considered, or the safeguard clause is to be invoked. The examples of severity classification given in Annex VIII are limited in number, and have little descriptive power to aid assignment. Additionally, the examples given often relate to the procedure and do not attempt to assess the outcome, such as adverse effects that may occur. The aim of this report is to deliver guidance on the assignment of severity, both prospectively and at the end of a procedure. A number of animal models, in current use, have been used to illustrate the severity assessment process from inception of the project, through monitoring during the course of the procedure to the final assessment of actual severity at the end of the procedure (Appendix 1).

Potential for unintended consequences of environmental enrichment for laboratory animals and research results.

Many aspects of the research animal's housing environment are controlled for quality and/or standardization. Of recent interest is the potential for environmental enrichment to have unexpected consequences such as unintended harm to the animal, or the introduction of variability into a study that may confound the experimental data. The effects of enrichment provided to nonhuman primates, rodents, and rabbits are described to illustrate that the effects can be numerous and may vary by strain and/or species. Examples of parameters measured where no change is detected are also included because this information provides an important counterpoint to studies that demonstrate an effect. In addition, this review of effects and noneffects serves as a reminder that the provision of enrichment should be evaluated in the context of the health of the animal and research goals on a case-by-case basis. It should also be kept in mind that the effects produced by enrichment are similar to those of other components of the animal's environment. Although it is unlikely that every possible environmental variable can be controlled both within and among research institutions, more detailed disclosure of the living environment of the subject animals in publications will allow for a better comparison of the findings and contribute to the broader knowledge base of the effects of enrichment.

Method to quantify tail vein injection technique in small animals.

Injection errors, which are often not readily recognized, can greatly impact the outcome of a pre-clinical research study. As a result, unrecognized misadministration of test compounds can render a high cost to the biomedical community. In this report, we propose six criteria for a reagent designed to assess tail vein injection technique in small animals and suggest a reagent, colloidal gold labeled with the stable isotope 197Au, that satisfies these criteria, thereby describing and validating for the first time a method to quantify technical compliance in tail vein injections. In an application of this reagent, we show the degree of variation experienced by technologists performing tail vein injection procedures in mice. In this study, mice were manually restrained and received an injection in the tail vein. One hour after injection, the mice were euthanized, various organs including the tail (the site of the injection) were collected, and their gold content was quantified by neutron activation. The three experienced animal technologists in the study were tested for tail vein injection proficiency in 30 mice. Prior to the study, the supervisor stated that a misinjection occurs when more than 10% of the intended volume remains in the tail. In light of this criterion, 12 of the 30 injections were misadministered: two with technologist 1, three with technologist 2, and seven with technologist 3. Although she was able to correctly rank the injection skills of the three technologists used in this experiment, i.e., technologist 1 and 2 more better skilled than technologist 3, the supervisor greatly underestimated the extent and degree of injection failures for the procedure. The results of the study illustrate the potential problems associated with the technical compliance with this common laboratory procedure and suggest that there is a need to validate injection methods and a need to monitor technical competence. Application of reagents similar to colloidal gold and the methods presented will facilitate the development of improved methods of teaching injection technique and monitoring technical quality in the laboratory setting. In Vivo Micro Computed Tomography of Subchondral Bone in the Rat After Intra-articular Administration of Monosodium Iodoacetate