I once had job where 2 cows with calves escaped and went wild in cornfields for about a month. Landowners had several deer bow hunters carry a tranq gun in hopes of getting a shot, but the cows were very sharp and played the wind and managed to avoid them all. They hired me and gave me the gun and darts with enough juice for an adult cow, or so they said. I located them in a forest and spent about an hour sneaking up on them down wind, but before I could get in range the wind swirled and they went crashing into to corn field. I could hear them sticking to the edge of the field so I went into the middle and tried to get ahead to wait on them, but when I got to the edge there they were. I darted the nearest one clean in the rump and they ran off. I thought it was money in the bank. Followed the tracks and found them in someone’s backyard about quarter mile away, the right amount of time had passed so I just walked straight toward them expecting one to be down. Nope, one was a bit tipsy, but they all ran off. No one ever got another dart in any of them until late fall when they decided to kill the two cows. That worked, the calves stayed close and it took 7 darts full of juice for one calf and 8 for the other. Apparently they were a type of cow that is not sensitive to the tranquilizer. They were those black ones with the big white stripe in the middle, Viking breed or something like that.
Yes, a vet had to be involved when we used the tranq gun.