Black specks on your dog or in your dog's bed may be “flea dirt” – the fecal matter from adult fleas. There are two easy ways to check for black specks: Run a flea comb over your dog, making sure the comb reaches the skin through the coat. ... If black specks appear on the towel, it may be flea dirt.

Does flea dirt mean an infestation?

If you collect anything that looks like dirt, drop it into a bowl of water; if it's flea dirt, it will dissolve into a reddish-brown stain in the water. Also, even if you only spot one flea, you could still have an infestation. ... Fleas thrive indoors since most of us keep our homes climate-controlled.

Why do fleas leave black specks?

Flea dirt is one of the primary indicators that your Lab has fleas and that you need to take action. These small black specks are flea faeces and materially are composed of old blood.