Used sedalin for the first time this year to clip my difficult mare. Was fab!!!!!! She was nicely chilled but not sleepy and let me get on with the job. Apparently it doesn't work for all horses but I guess that's true of most things. Worth a go imo.
Sedalin is ACP. Well more or less. It is dope for horses. Unfortunately different horses react differently to it. Some need a lot and some need hardly any to be completely zonked out. I think it basically just makes them sleepy and out of it. Sedalin comes as a gel you administer about an hour before you want a nice sleepy horse. It is prescription only so has to come from the vet who will be able to advise you on a likely dose for your horse.
My big brown horse is massively susceptible and will sleep all day on the dose you would give a pony. My old horse was the complete opposite and had to have a tonne for any effect. With him it was easier to get the vet to come and dope him intravenously.
It's used all the time though for things like the dentist and the only real precaution is to make sure you keep your horse and keep a watchful eye on him/her until it wears off. I certainly wouldn't hesitate to use it if I felt it necessary.
It it possible you can get your horse a bit more used to having it's mouth played with before the dentist comes back so maybe you can go without? I always prefer to try and work through these things before resorting to the dope.
Sedalin got me though the first 2 years with my horse! Its amazing stuff, he was un shoeable without it, dentist couldnt get near him I couldnt pull his mane but only 2.5ml and he's anyones!
ACP does not work at what ever dose, weirdly as i believe its the same but in tablet form!
I recommend it but as others have said it won't work for every horse.
I used it a few times....it does have the dose on the box but its better off to ask vet for dosage advice as it really does depend on the nature of your horse ie the box says for mine....a quarter of the syringe. vet said to use the whole syringe. so a big difference, and after trying a quarter syringe at another time..it did nothing. the full syringe worked just fine. make sure you give it when the horse is relaxed though..it wont work if they are already hyped up about something.
I used a half a syringe of Sedalin to get my mare clipped who was absolutely terrified of the clippers. (We spent a week desensitizing her first) It worked brilliantly,she was nice and chilled, but she was very sleepy all day afterwards!