Table 3
Experimentally determined technical and safety parameters for comparing different approaches used with rigid endoscopes (equipment set-up 1) during thoracoscopy of calves chronically affected with BRD

Approach^a	VSa vs. b P = 0.012	PSa vs. c P = 0.022; b vs. c P = 0.01	RTP = 0.101	RLa vs. b P = 0.012
Ventral (n = 2)	2 (2–2)^a	3 (3–3) ^a	3 (3–3)	3 (3–3)^a
Mid (n = 5)	3 (3–3)	3 (3–3)^b	1 (1–3)	2 (2–2)
Dorsal (n = 1)	4^b	4^c	3	1^b