My Dog Has Black Dirt Looking Spots All Over Her Body. What Is It?

My dog has large black patches on its skin that it did not have as a younger dog.  Under the bed is a dark smelly area also.

Is could be flea or tick droppings check your dog All over for tick or fleas if you see any get flea and tick shampoo, and use it while bathing never do a flea dip were you put the in a tub of only flea and tick shampoo because it will cause liver damage, first wet the head and apply the shampoo because when the dog gets wet the first place the fleas and ticks run is the head be very very very very careful to not get the shampoo in the eyes at all and don't get it on the nose or water up the nose wet the body and make sure you scrub every inch of the dogs body with the shampoo ad let the dog sit or about 8 mins the rise very well and check the body for any dead  fleas or ticks, if you see live ones do this again. I hope I could help