Table 2.

Overview of the number of studies selected and removed at each step of the PRISMA flow diagram for conducting a systematic review (Fig. 1).

	Identification		Screening			Eligibility		Meta-analysis
Host species	Database [A]	Other [B]	Total [C]	Duplicates [D]	Excluded [E]	Total [F]	Excluded [G]	Included [H]
Domestic pig	95	6	101	50	36	15	4	13a,b
Sheep	53	7	60	30	19	11	6	6b
Cattle	45	4	49	23	20	6	3	3
Wild boar	44	0	44	11	27	6	0	6
Moose	17	0	17	10	3	4	0	4
Total	254	17	271	124	105	42	13	32

a = Number of studies increased during the data extraction process. Lind et al. (1994) reported two studies on domestic pigs. b = Number of studies increased during the data extraction process. Eglīte and Keidans (2000) reported two studies on domestic pigs and two studies on sheep.