I came accross lots of idiots, unfortunately. One of them rang RSPCA because thoroughbred yearlings had no rugs on them in winter...
Similar experience with a phone call informing me of a "white van" parked up and "someone in the horses field". Went down to find two uniformed members of a well known animal welfare organisation, there as a result of a report of a "horse seen limping with something wrapped around its leg"!
You would have thought any idiot would have seen the "something" was in fact a bandage but no, a vet had been summoned to assess the horse!
Under threat of calling the police if they didn't immediately leave my land, I subsequently telephoned my own vet, passed the phone to the inspectors in order they could be informed by my own vet that the horse concerned was in fact under medical care.
A couple of weeks later, I received a bill from the vet called by the RSPCA, for a call-out fee!
Worth remembering that sometimes it is not the owners at fault, but the interfering local busy body as in our case, and especially where a public footpath runs next to the field. We later caught her in the act of emptying a couple of bags of grass cuttings over a fence, in a spot where previously we'd found old bread and cake dumped!
She thought "supplementary" feed was called for as there didn't seem to be much grass available.
It actually took a hand delivered, signed-for letter from our solicitor threatening legal action, in order to curtail her activity.