I've had 3.
The first was shortly after I bought the truck and camper. Weight is about 11,500 on a DRW F350. I came around a gentle corner on a rural highway and there was a herd of cattle in the road. My truck doesn't have anti-lock, and the back end wanted to slide even with all of the camper weight on it. I got stopped in time and pumping the brakes avoided too much of a flat spot on the rear tires.
The second was 2 years ago. This time it was deer in the road at night. This time I was hauling a utility trailer with a combined weight of about 1,500 lbs. No trailer brakes. This time scared me bad. Turns out the slack adjusters weren't working on one side in the back, and I wasn't developing full brake pressure. It wanted to slide the front tires and not stop firm. Fortunately the deer wandered off. I fully rebuilt the rear brakes as soon as I got home; basically I replaced everything on the backing plates. This is one of those things where it was happening slowly so I didn't notice the gradual reduction in brake effectiveness. The difference was drastic after and it took a while to get used to the returned strong braking.
The third time was out in Eastern Washington when a mule deer walked out in front of me. It was HUGE, his shoulders were above the level of the hood. He slowly wandered across my path. I was doing about 65 (right at the speed limit out there). I got down to 15 MPH. I thought I could pass him on the left, and went completely to the left edge of the road since there was no oncoming traffic. Just as I got to him, he bolted and I hit him dead center. It knocked him down, and he flopped around a bit before getting up and running away. It broke the grill and a headlight trim piece. The two oldest kids were riding in the dinette and were shaken up a bit by the panic stop but were otherwise unhurt.
