She might just be shocked, by what happened getting run over by a horse that is a lot bigger than you is scary so hopefully she is just in shock and will be on her feet in no time.😀
It could mean a disease but if he is acting fine than I don't know, but if the reason of the swelling is because of a bee sting I feel like it would bother him does he react when you touch the area.
Give her some nutri drench in her water it will give her a boost and some apple cider vinegar in a separate bowl of water,gape worm is not contagious but if the other's have it then it is because they all ingested it.
Do the following,use flubenol it is a powdered worming product.Or you should...