I haven’t seen a clinic policy about this in 3 different practices, but I have some personal rules. If they’re beligerent or I’m acually at risk – abort mission. Your insurance will cover it, but then you might not be able to work. Is that really worth it?
There are a few different oral sedations I’ll try before quitting entirely, but I always tell them that I can’t safely do x, y or z and it will be safer & cost less to find a trainer to work with them and their horse. I try to suggest a few people who are good with difficult horses, although in some areas, this has been very hard because the locals have poor reputations. I don’t offer to do any training, but I will go touch some horses every time I’m at certain barns. The BEVS “don’t hurt your vet” youtube videos are where I send everyone with needle shy horses. I also have a pole injector on my truck for IM dosing over a wall or through a fence (but I’m not very good at it).
I always charge for the dose of sedation I actually use, don’t loose money on someone else’s poor training, just point them in the right direction. I haven’t had owners judge, but we talk about how I can’t get hurt and keep treating horses, and my oncall group will be down a vet. I tell them that if this horse gets hurt or sick, nobody will be able to help them because we can’t take a temperature, get blood or stitch it up. If the horse is only reactive around the vet, I recommend they bring in other horsey people and trainers so there are just more hands on the horse over time. I’ve had horses go unvaccinated and I’m ok with that. I’ve euthanised horses when they’re sick enough to touch.
Eventually, its up to the owner to do what’s best, and “you can’t care more than the owner”.