Even if you don't find any fleas on your dog, they are skilled at hiding, with even a few able to cause a problem in allergic dogs. (dog-health-guide.org)
Finding flea dirt on a dog or cat is one of the best ways to diagnose an infestation. (fleascience.com)
That is why many dog parents can not find any fleas on their dogs despite their dogs have severe and persistent itching. (natural-dog-health-remedies.com)