One of our lactating does has begun developing small lumps or bumps on her teats and udder, just in the past week or so. On some of them I see a whitish spot at the tip of the lump. They are roughly between the size of a pea and a blackberry. The last couple of days, another one (or two) seems to pop up each day (milking once a day). Not sure what may be causing this or just how concerned I need to be about it. Any thoughts?