[Morgana]

but I thought some dogs chased cows! Don’t sheep dogs do that to “round them up”?

[DivineMomentsOfTruth]

My Border collie would be a goner. Glad I don’t live there!

[Tammy8]

Well trained stock dogs work the livestock in a quiet, controlled manner which does them no harm, and keeps stress level down of the livestock so doesn’t interfere with health, growth, or weight gain.

That is far different than untrained dogs running stock for the fun of it. Not to mention the chase at some point if not ended will end up with dogs actually physically injuring or killing livestock.

[RedMonqey]

"but I thought some dogs chased cows! Don’t sheep dogs do that to “round them up”?”

Yes, some breeds of dogs are trained to help round up cattle but "Donald Trump" was the rancher's dog, wasn't the right breed and wasn't rounding up the cattle.

It had killed the rancher's livestock, was warned to keep his dog under control and was promptly shot as a nuisance dog.