oh no J!!!!! pardon me, but WTF
! I hate when crap like this happens and people are like "oops, i didnt think it was a big deal". I had roommates a couple of years while in college and I hated that my peace of mind relied so much upon the actions of others. As for the girl that left you high and dry I believe you can take legal action against her given your lease has her name on it as well as well as some other stipulations (However, I dont know how it goes if one roommate "evicts" another).
I'm sorry this happened to you but agree with the other posters. If it truly is as bad as it sounds perhaps you should seek the help of a professional. Poor Meeko
once you know he is free on fleas do you have a friend in your building or a neighbor who could maybe look after him so he is close to you and wont get re-infested with fleas.
If you need to vent anymore or just wanna get out of the house we can go out for coffee or something or you can give me a ring to just complain.
Dont worry everything will be better by next week or so
Hugs,
V n B