hitch a ride

I went to a friends house to feed her cats on Monday. On Wed I brought her home from the hospital and her cats are infested with fleas.  I have 2 cats of my own but they have Frontline monthly.  My friend thinks I gave her cats the fleas.  Can they reproduce in 2 days if one jumped on the cat? (Its winter here in Ohio)

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I found a flea on our dog yesterday. She has never had any on her before. She is treated with Advantix for 7 months of the year. A visitor came in the house a few hours previous to finding the flea and he has a cat and had just been around someones dog. Is it possible the flea came in on him? We will continue to check the dog today but I am hoping this is an isolated incident. Your thoughts please.

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