i don't know how to sedate an emu, but I know you can lead them into a stall,horse trailer etc... put a dark sock over their head to calm them and make them lay down. Might have to ziptie those legs together. If your emu is tame enough I'd put down a tarp, kiddie pool etc.. in a small enclosed area, fill it up with as much warm water as you can and add epsom salts. Have the emu stand in their and that way it will be soaking it's foot while standing or if they are like mine they will lay down. I'm not sure what antibiotics are safe for them.....epsom salts work good for a lot of things. You can also take some corral panels and make a squeeze shoot to hold them in one spot, but the calmer they are the better for you. I would talk to a local vet about the antibiotics but I know I give my emu horse EE & WEE plus tetanus shots as well as West Nile, so that might be helpful to give a tetanus shot. If you can get it to lay down, then take a large syringe full of epsom salt and flush the wound, then some iodine and vet wrap. Be careful........ I clip mines nails some before I handle them, just encase.....