How do you know if your dog has fleas?
Usually if you part the hair and look at the skin near the eyes, on the tummy, under their legs in the "underarm" area, or on the back end near the tail, you can see them as tiny dark brown or blackish shiny spots that might be moving and hopping. But sometimes the spots are not the bug and aren't moving, but rather the excrement of the bug, another sure sign that there are fleas hiding somewhere.
You can also get a flea comb, which is a comb made for the purpose with very fine teeth, that when combed through the coat will pick up the fleas and you will see them on the comb (you may need to hold it over something white to see the best). Some people also hold something white near the dog's skin, such as a piece of paper, a white sheet, note card, etc. and then rub the dog's hair and skin lightly but briskly with their finger tips...this can make the fleas hop and you will see them when they land on the white background as tiny black or brown spots.
Another big clue is if the dog is scratching a lot and especially if chewing on places where the fleas are using his front teeth, trying to kill them between his teeth. This may be due to other problems such as allergies or skin disorders, so you should be sure to confirm there are fleas before treating with flea medicine. You can also avoid using the flea chemicals if you have a small enough dog to carefully comb them with the flea comb over every inch of their body and coat until the bugs are gone. Repeat this several times over a period of days and then check and use the comb every few days to catch any missed ones or newly hatched ones.
If your dog has fleas and you treat the dog, but DON'T treat your house and the dog's bedding, not only will the fleas jump back onto the dog (or any other animal in the home) but you'll likely also find them on yourself, your bedding, in the carpet, etc. The optimum treatment is to treat the dog, the dog's bedding, AND the home in one fell swoop.