My horse is going to have a pastern artherodesis on Monday, and so she has to go fully under anastetic, i'm really worried about this please can someone reassure me?
I have no experience with the condition but had a great big mare that needed to going under a full anaesthetic a couple of times and the vet said it took a lot to get get out and she was always fine after.
My 17hh MW who weighs 750kg had a general anaesthetic a few months ago and I was really worried as you are but he was fine, came round no problems and when I saw him the next day he was back to his normal cheeky self. Hope it goes OK.
My boy had the same operation but in his hock about 12 weeks ago. I was just like you and was terified but he was fine. Apparently came around very well after the operation and all was fine. Vet rang me as soon as it was all over.
My boy had knee surgery last month ~ he as put out. I too was really worried as he was considered higher risk because of his weight but thank the lord he was just fine.
The GA risk is not so high for horses lying on their side, as yours will be, compared to those on their back, such as for colic surgery. It also won't be a massively long surgery (I know it will feel like it while you're waiting!) and for this non emergency surgery, I'm sure the vets wouldn't be doing it if they thought their was any risk from him being overweight or with any heart abnormalities. So in short, try not to worry and I hope it's all good in the end. Go buy your pony a pressie - it always makes me feel better when something goes wrong with mine!