The farmer threw the cow over the fence some hay
A. The problem with this sentence is not a dangling participle but a misplaced modifier, which creates confusion about what the farmer threw over the fence.
A dangling participle begins with a participial phrase (-ing phrase). It also creates a problem with modification because the word which the phrase is intended to modify is not in the sentence.
Example: Rushing out the door, his sample case was left on the dining room table.
It sounds as though the sample case is rushing out the door.
Corrected: Rushing out the door, he left his sample case on the dining room table.