What does one do, flanked by trashy, indifferent neighbors?

Let me introduce you to my neighbors on either side. On one side is a young married couple. The wife is Vietnamese and the husband is an American working as a teacher at an English language center. They have a toddler and a newborn baby.

They do not use a trash can but put all of their garbage in a plastic bag and place it in front of their door for sanitation workers to pick up.

But on many occasions, since they discard trash more than a few times per day, the bags are not cleaned up right away but end up being torn apart by either dogs or rats. As a result, garbage, including baby diapers, gets scattered around, dirtying my house's front yard.

When I asked them to use a trash can, they solved the problem by putting their trash (secretly) into the bin of their neighbor next door. After some time, when the neighbor moved away, they (secretly) switched to using the bin that my family has bought in collaboration with the owner of a rice warehouse on the other side of the street.

When our trash bin overflows, I am the only one who cleans it up.

I called on the landlord who rents the house to that couple. She took it forward in a non-confrontational manner. After that, for a while, the couple placed a foam box in front of their house to keep garbage. Not long after, status quo returned.

There have been times when I was so angry that I picked the garbage bags they threw into my bin and placed them in front of their house. They dealt with this situation by throwing those bags in some other trash can in the neighborhood.

Now, the neighbors on the other side have a dog they lock up in a kennel and place it in front of the house. Unsurprisingly upset about being locked up, it barks fiercely, non-stop, till it gets tired.

The neighbors only let the dog out for urinating and defecating, and they never clean up the mess. So it stinks every time it rains.

Sometimes, their kid throws stuff, including plastic bottles or bags, at the dog. This is playtime. These "toys" are then left scattered on the sidewalk in front of my house after the fun is over. No one cleans up after, of course.

I am stressed out. At a loss. What do I do now?