dragoneggs, you raise a very valid point. There are definitely more potential obstacles than just a family pet. Most folks have heard of them incidents too, because they are fairly common and especially in rural areas. Typically though, wild animals have a bit more fear of roads than do domesticated animals. If they did not there would be plenty more wild animal casualties given their population likely exceeds that of domesticated animals.
There are risks in just about every thing and humans tend to mitigate those risks with control. When a person takes ownership of something they should also accept the responsibility that comes along with ownership. Even ownership of inanimate objects requires assumption of responsibility, such as automobiles, for example. The problem with live animals is they have ability to do things on their own accord whereas a gun, auto, or whatever requires manipulation by an external force.
If we as owners do not mitigate these risks then other peoples lives and livelihood (cattle) may be in jeopardy. If we are unable to provide responsible ownership then the ownership should be relinquished.
I'll give you one more example and then step down off my box... 29 years ago my family was riding in the car with me one Sunday afternoon in a small rural village. Speed limit 25. A small dog darted into the path of my vehicle and was run over. My children felt it and knew what happened. Old enough this bothered them to tears and they still remember it, as do I. What was worse was me making the walk to the door steps of that house and telling the adult inside that a small dog was just run over. He wasn't too bothered but those two small girls were horrified. I will never forget that day.
Pet Owners be responsible.
Jeff