Can my dog still have fleas if there are no signs on them?

Yes. Any pet can pick up fleas; any pet can have fleas. Some products repel, just like you and I put on bug spray to repel mosquitoes, but a lot of the preventative products that we have here require the flea to bite the pet to uptake that medication kills them, so it's possible.

Yes, it's possible for a dog to have fleas even if there are no visible signs. Vets may find fleas on a pet that the owner believed was flea-free by using a flea comb or looking for flea dirt. If a dog is not on any type of prevention and comes in with itchiness, the first thing vets will consider is flea allergies.