One last thing I just thought of. When doing lymphatic drainage or any massage actually the client (In this case your gorgeous filly) may feel a bit off for a day or two after as the toxins caught up in that massive swelling starts to shift and put a bit of pressure on the kidneys and liver to try and get rid of them. I would expect that she may drink more then usual and her pee may be a darker colour and she just may be a bit less bright and bouncy. Dont be worried if that is the case. It will disappear very quickly. I would do a shorter massage for the first one so she doesn't get overloaded say five to ten minutes if she will stand that long. Then later on say three days time give her longer if you want to. You dont want to do this massage when there is an active infection going on as it might spread it which is why earlier would not have been good but now would be great.