Glad you worked it out!, I do have a few other comments, Take them for what it's worth.
I work for a veterinarian! While fleas can be an issue, with a bit of persistence, it's not that big of a problem to solve.
That said, it's insane, how someone will pick on the one member of the family that can NOT defend itself.
As to his friend who lives in filth, and probably is not taking care of their pet. TURN them in to you local police or animal control!
I see way to many neglect cases. And in our small community one horrid abuse case, where a guy beat a 10 week old puppy to death because it chewed up his cell phone charging cord. I am happy to say, because it was reported, and thanks to a video on my cell phone, the abuser is now doing 5 years in the state pen. It won't bring the puppy back, or relieve what she suffered before she died, but there is a bit of small solace in the justice.
5+ year maintainer.
The human body is capable of amazing things! But without the mind, it is nothing. Get your mind in gear and the body will follow!
Be selfish about caring for yourself, you deserve it!
Weight Watcher leader! But always a Member first!