**7. Conclusions**

In spite of a substantial body of evidence investigating welfare associated with blood sampling techniques in mice, it was concluded that there was not enough, high-quality evidence to make any recommendations on the optimal method of blood sampling from the point of view of animal welfare. Future high-quality studies, with standardised outcome measures and large sample sizes, are required.

There is an urgen<sup>t</sup> need, as highlighted by many authorities, to increase quality (and/or reporting) of animal research at all stages from inception to reporting. The use of guidelines such as those published by ARRIVE [64], and protocol registration, can assist in achieving this. Journal editors also need to advise researchers of guidelines and enforce provisions, which will no doubt serve as an educative as well as compliance function.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2076-2615/10/6/989/s1, Search strategy, Table S1; risk of bias determinations, Table S2; Results of vote counting based on direction of effect, Table S3; Full extraction templates, Table S4.

**Author Contributions:** Conceptualization, A.L.W.; methodology, A.L.W. and T.H.B.; data curation, A.L.W. and T.H.B.; writing—original draft preparation, A.L.W. and T.H.B.; writing—review and editing, A.L.W. and T.H.B.; project administration, A.L.W. and T.H.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This review received no external funding. A.W. is supported by an Australian Government, NHMRC Peter Doherty Biomedical Research Fellowship (APP1140072).

**Conflicts of Interest:** The author A.W. was an author on one of the included studies. [26] T.B. made the final call on decisions relating to inclusion of this article and the risk of bias determination. No other potential conflicts exist.
