About a year ago during winter one of my hens got severe frost bite on her feet. She lost basically all her toes, save for her back thumbs and half of a toe on one foot. The dead tissue fell off and it healed okay. She has done well since then and gets around okay, although a bit wobbly. But now I have noticed a new scab on one of her feet. I noticed this a few weeks back, but it was more loose and hanging there and didn't look like a scab. It kind of looked like skin with sectioned parts... it's very hard to describe. I figured it would just fall off and then heal. I looked at it again recently and the scab isn't as loose and looks more...well... scabby. She is laying, drinking and eating, and seems to be doing fine. Is this something I should be concerned about?