Nightmare Tenants that is always pushing the boundries

[Beverly Lafia]

I have a nightmare tenant who is always pushing the boundaries of what is legal.  She lives in a triplex of mine and has taken over the whole front of the triplex. She has so much junk..which isn't that a fire hazard?  She has blocked it off and says this is her private space because it is in front of her porch.  I inherited her. She hasn't had her rent raised for the whole10 years that she has lived there, due to the last landlord being scared of her.  She is always writing lengthy letters quoting the housing laws and having mysterious health issues. After the pandemic, I started to raise her rent the allowable rent every year, but at this rate...

So the issue now is she has two cats already and then one day i go by, and there is a loose dog running around the property. She said this dog is her emotional support dog and then gave me a letter from her mental health provider.  Do I have the right to ask her to sign a addendum to a lease?  She is still on her current lease from longer than 10 years ago.  She is a nightmare and asks for the world.  Now the real issue is the other tenant has now written me a lengthy letter saying she is scared to address the issue because of repercussions from this woman. There is dog poop and the property is starting to smell.  The other tenant is not able to walk onto the property without the dog jumping on her and scratching her all up.  I am at my wits end with this. 

Do I have any rights as the landlord?  I called the health dept and they said ultimately it is my problem. Besides hiring a gardener, can i issue rules for the common area and fines for breaking the rules?