Table 1.

Risk of Bias summary table (✓ = yes, ✗ = No, UC = unclear).

Study	Selection bias			Performance bias		Detection bias				Total Score (Max 9)
	Randomization	Baseline characteristics	Allocation concealment	Random housing	Blinding	Random outcome assessment	Attrition bias	Reporting bias	Compliance with animal welfare regulation
Jing et al.2019 [15]	✓	✓	✓	UC	✗	UC	UC	UC	✓	4
Fuchs et al.2003 [16]	✗	✓	UC	UC	✗	UC	✗	UC	✓	2
Tang et al.2018 [17]	✗	UC	UC	UC	✗	UC	✓	UC	✓	2
Muller et al.2014 [18]	✗	✓	UC	UC	✗	UC	✗	UC	✓	2
Jong et al.2016 [19]	UC	✓	UC	UC	✗	UC	UC	UC	✓	3
Bonda et al.2014 [20]	UC	✓	UC	UC	✗	UC	✓	UC	✓	3
Dawn et al. 2004 [21]	✗	✓	UC	UC	✗	UC	✓	UC	✓	3
Hartman et al.2016 [22]	✗	✓	UC	UC	✓	✓	✓	UC	✓	4
Kobara et al.2010 [23]	✗	✓	UC	UC	✗	UC	✓	UC	✓	3
Kaminski et al.2009 [24]	✗	✓	UC	UC	✗	UC	✓	UC	✓	3
Hilfiker-Kleiner et al.2010 [25]	✗	✓	UC	UC	✗	UC	✓	UC	✓	3
George et al.2021 [26]	✗	✓	UC	UC	✗	UC	✗	UC	✓	2