Oh Gawd! Poor Casper and you Kate! I think Barbara did something similar with Riley ( not sure if it was spelt flour though ) and described the look in the house as akin to 'Murder in The Bakery'
Oh no! Poor Casper..... I nicked Charlie and made his nail bleed - but it wasn't dramatic. Maybe it depends on how much you cut? It bled for a few minutes, and I pressed a clean towel to it, and then it stopped. It reminded me of a cut on, say, the end of your finger that produces a load of blood for a bit (but still, not all that much....).
If I am doing nails I keep a thingy (got it from a pharmacy) in which stops bleeding it helps coagulation. You can get them at most places. I've always got stuff in like that cos I'm a bit of a bleeder myself. if you cant find anything else apply pressure and elevate the bleedy bit.