The phrase "live fleas" means that there are actual fleas present, which are small, biting insects that can be found on animals or in certain environments. Full definition
This is why dog owners often don't see live fleas on their dog unless there is a severe flea infestation in their immediate environment. (glenerinanimalhospital.com)
Given these huge numbers, it is entirely possible to see live fleas on your pets that have been treated with flea medications. (bigcountryvet.net)
Most pet owners complained of live fleas present despite the application of topical flea control. (animalbehaviorcollege.com)