I have had a few of those over the years... Embarrassed to say but I neglected the nail clipping and his nails would randomly break off like that. No pain, no blood and just a little "shedding". I always thought bc he gets lots of walks outside on the pavement and a little clipping at the groomers twice a year (he's a red legged Yorkie so fine and wirey hair, slow growing) that was enough. Now that I clip them regularly, I haven't had the shedding. Was alarming at first to see but in relation to how long the nails were it wasn't all that bad. Again bad on my part