Oh my goodness...I'm sorry to be of no help, but I have no idea. Everyone still seems fine? I take it you found more blood than if, say, Lucy shook her head after you tested her? Trix has done that after getting her ear poked at times, but it doesn't amount to a huge mess.
BTW, in order for the forum to see your latest status update (in this case, your question about finding the blood), you need to edit the subject line of your very first post.