HELP! red and purple on her foot!

The other weekend my mare got her feet done and she has been lame for a while now, and he found an absese. So I've soaked her foot 3 times in epsom salts and betadine, and wrapping it. She is barefoot and she use to be shoed. And like the 2 day I stared soaking a red line showed up and I didnt know what to think so I stopped soaking for 2 days. And we have a huge flood! So I wasnt able to go look at her feet. And today I looked at her foot and found this! THis is the spot to where the red line was. Please help me! The farrier is coming out monday to look at her to.

Bruising. Shouldn't cause a problem. Did the abscess burst, and is she sound?

No and no

Who found the abscess--the vet or farrier? And what did he say should be done about it? How did he know for a fact it was an abscess?

It was the farrier. He found it on the bottom of her foot. He told me to soak it and to wrap it it to keep it clean. This isnt the same horse, my other horse got the vet looked at and he said he had bruising.