My horse cut her leg on loose wire, anyone have any suggestions to reduce swelling? :(?

I board my mare at a little acreage, it is clean and nice but for some reason there was loose wire just laying there from when they did their electric fence. I am shaking my head at the fact that someone thought nothing of it and just left wire in the middle of the pasture. She got it caught around her right hind leg, cut it just below the knee. The cut is clean and not that large, I cleaned it out with sergical soap, applied some polysporin, gauzed then wrapped it up. It is swollen all the way down to the hock, and she is lame to the foot completely. She won't put her weight on it, it's the worst limp I have seen. I am completely broke I just had a baby and I am freaking out. I am going to try to get the vet out as soon as I can. I feel so bad for her seeing her in pain like this is just killing me.. Should I be really worried about her limp, does this sound completely bad? or is their hope...