Their dog was still living their (without them) up until two days ago...

I don't want to go into the full list here for the purposes of privacy but let's just say that apart from property violations, the tenant is also violating the pet policy and having multiple inhabitants residing in the house.I am in talks with an attorney who suggests that we start with a 3 day cure or quit. 

They've added two dogs (against the lease).

For example, if a renter books the property, by that action, they are also agreeing to all the terms of agreement such as no pets, check in and check out times, additional cleaning fees for excessive use, deposit for any damages, etc., thanks!

It is easier in that case to say Hey how about you teach me how to do this and I will do some "bird-dogging" for you? 

(current rental rate, pets, jobs, etc.) 

A con is that every time we have someone staying in the guest suite, I have to walk my dog on a leash so she (german shepherd) does not go scare our guests.

Party all night, play loud music, literally go bowling on the floor above them, do all your farting in the common areas, get a small dog that never stops barking, etc.

One tenant has a dog and cat in violation of the lease and unit is in worst condition of the 4 because of neglect and the pets.

It'll cost the same probably and mine here in OR is well worth it since she does everything including postings.4) Having said that, I'm in wine country in OR and I let in max guests and pets since I have plank lino throughout.