It looks like the local authorities are not living up to their responsibilities. I would:
Show up at a city council meeting and say something
See if you can find (on the internet) a couple of local dog rescues. Not only are these dogs a noisy inconvenience for you, but they are living horrible lives and deserve better. Snap a few pictures to send along to the rescue.
Rescue folks have hearts of gold and they can be very effective getting stuff done if they see a situation that is inhumane.
The fence is a great idea, put it up ASAP.

I have a somewhat similar situation across the street. My township has been good about doing as much as they can but there are no laws against being a slob. I found that keeping the pressure on them helped a lot. They had many cars in the street and the moment the registration sticker expired the neighbors were on the phone complaining and the cars were ticketed. They had one car blocking the sidewalk and that was ticketed, too. Another car was under a tarp in the backyard and they were forced to remove that.

They also have screaming fights with foul language so we report "domestic violence".

They usually calm down just to avoid visits from the police.

I'm sorry to hear your local law enforcement is not helping you.I do believe the animal rescue groups are usually responsive, so keep trying with that. Do you have a commissioner? They can often be helpfu.l

Take it from me, you can change this. I changed an entire neighborhood, but it took unrelenting persistence, political pressure and working to change ordinances that were outdated, too lenient and not working in our favor. If you don't know what your ordinances are, print them out and learn them. Note every one that is being violated by your 'neighbor'.

I don't know where you live or what your city's governing body is like. If you have one councilperson who represents your area, then take photos and ask your neighbors to do likewise. Make an appointment with that councilperson and make sure several of you go. Select one spokesperson and present your case, using the ordinances as evidence that something must be done.

I virtually lived at city hall. I got to know *everyone* - and they knew me and knew I meant business. I can't stress enough how important it is to be there in person, to form working relationships with those who have the power to enforce your city's laws.

What you describe sounds very much like a meth house. We had those - and we closed them down. Visit your local police precinct. Make an appointment with the commander if you can and go in with documentation, especially about the "steady stream of cars."

As for the poor animals, take photos, lots and lots of photos. Make an in-person visit to whatever organization is responsible for the welfare of animals. Lay out the photos and describe what you are seeing, day after day. I can't believe you won't get action, but in the event you don't, go to the media. Pick a TV personality who has a great reputation as an investigative reporter. Make an appointment if you can, go in with your neighbors and lay out your photos and your concerns. Welcome to TV land. Make friends in the media, don't let the issues drop.

I started the effort in my neighborhood, but I did not work alone. I gathered everyone who had the same concerns and we worked together. It did not change overnight, but we stuck together and everyone at city hall knew we were not going away. You can change that situation if you have the will to persist.

Thanks for the advice. I'll have to make visit to animal control with the pictures and video that I took of the situation i described in my first post. The odd part is that the neighborhood is not ghetto by any means - there are several professionals living here (even some that have influence over city officials) which makes it even more odd that nothing seems to be happening) and the yards and homes are immaculately maintained. We just have this one home that is horrible. Additionally, I have scheduled a fence to be installed next week :)

The house to my north was occupied by a divorced dad. He had his daughter to the house on a regular basis, but for never more than a few nights at a time. When he moved into this new house, he had sod laid and then he watered. With the water going, we would leave for most of the day. That water ended up in my flower bed that was supposed to be high and dry.

He started a tomato garden, but never tended it. It became a weed patch. After two years, I would spray weed killer into the area and he didn't seem to mind.

Recently, he moved out. Just left on a weekend. No sign in front, no nothing to indicate what was happening. He let the grass grow and the weeds took over the yard. I mailed a letter address to "The Loser" at his address. I inquired if his mortgage people knew that he had abandoned the house, and followed up with a query whether they would be responsible of maintaining the yard.

7 - 10 days later, he mowed. Then, a yard service began taking care of things and it doesn't look too bad.

Maybe a letter address to "The Losers" might get some attention.

Gosh we had crazy drug selling neighbors and we did all that we "should" have done. Offered help, then went to the city, gathered the neighbors, had city council address the issues which resulted in them planting a city garden (right?). The house with the druggies got worse and worse, and one night we all came out when head druggy went nuts and tried to assault the 80 year old neighbor. Cops took forever to come even after multiple 911 calls.

We moved. Not fair but we moved. Turned out the main druggy was a police snitch (informant) so they let the neighborhood live in fear and drama for years while they planted us a garden. What a joke. Now that we moved there are three more houses on the block for sale. Sadly, sometimes you cannot fight a neighborhood in decline and if the city does not truly address the issue then your neighborhood is in decline.

I think you've gotten pretty good advice. Another idea is to contact a local news source, and give them documentation of the city's nonresponsiveness.

However, I would be pretty hesitant to stir up trouble if I were a single woman living alone (as I am) or have small children in the house, for fear of reprisal, especially if they are indeed druggies.

Still, I think face to fact chats with the police and your city reps are a good idea.

I like the idea of using the media. We have an 'iTeam' on one local station that investigates ideas given by viewers. As long as you are willing to be interviewed on camera or have someone that will be willing to do that, they will be happy to investigate. Once it hits the 6 o'clock news, usually things start to change.

UPDATE:

The fence was installed this past weekend and it looks awesome! Their junky lawn is totally blocked from my view. When the fence was going up, they came out of the house and mildly confronted the workers installing the fence about it's length, where the property line is located, etc. and did not seem totally thrilled about the fact it was going up. Too bad.

Additionally, I believe city codes enforcement and animal services may have came through, FINALLY. I noticed that a huge amount of the junk is gone from the front of the house, the yard was actually mowed, and the dogs are spending much less time in the enclosure. VICTORY!

Cubsfan,
I think this is a great beginning for you, the fence will help.
Jim-1, I guess I'm different, if it was a bunch of weeds and that was it I'd never send a letter addressed to 'the Loser'.
Unlike the OP's neighbor with the junk,dogs, and people coming and going, just overgrown weeds might signal owner illness or tragedy. The weeds still need to get gone, but there might be gentler ways to address the situation.

i have same problem like yours but mine is probably worse, Cuz im in between them and they do run the show in my neighborhood they got all my neighbors not to like me.And i live in my neighborhood for more than 2 decades and they are new in the neighborhood .I wave when they wave at me if they dont i dont.If they dont like me i dont care cuz they are not paying my bills but why destroying my property and i worked hard on my property i dont hire people to do my landscaping even my tree i cut my trees too but now everything is looking bad cuz they are spraying .I put cameras all over my house but it dont stop them. They are doing crazy things on my camera .I just ignore.it. I have no clue why they are doing it to me unless i got the nice yard in my neighborhood i keep my yard clean spotless.And one thing i was out of town and my son was the only one in my house they came to my backyard i guess my son showed them my backyard , i got nice backyard and i guess when they are in my patio one of the neighbor next to me said that "your mom is living in her own little world driving her cadillac" and i guess neighbor was all laughing .Im busy i keep myself busy in my house im a widowed and im doing everything in my house the maintenance and everything plus my daughter is a special need.I dont have the time to hang out with neighbor like them that they hangout almost everyday till midnight;, So what i did i invited them one time since they came to my house while i was out of town guess what nobody shows up ,And comes NEW YEARS EVE i always have party on New Years Eve cuz my late husband gave me a surprised party before he passed away so since then i have New Years Eve party , one of the neighbor texted me and invite themselves just the couple and next thing i know there will be 8 people so i said ok cuz the couple said they are also our neighbor , they came and in 10 minutes they left and only one couple say goodbye to me the rest they left without saying anything .I treid my BEST ....And i know for the fact if people are doing bad things to you theres something wrong with them.

. one day theres a barbecue in the neighborhood and they invited me an hour before the barbecue , and i look at the window and some of the neighbors are bringing bowl of food. And so i said thanks but i will pass cuz i knew im not invited they cuz if they want to invite me they will invite me one week or whenever they did plan it.And besides im not going anyway even they did invite me cuz of ny daughter when shes home we stay home.And i told them thx but my daughter is home now and she is special needs and txt me back said just next time.,

Not only killing my trees and plants they are spraying my drivway and my garages door and the outside walls of my house thats why the paint is coming off my wall and my screen too.When i put the camera what he did he spraying my plants and tress thru his oranges tree. I can tell where it coming cuz u can see the hole his making to destroy my property my furniture on my patio , my heater , my barbecue island my pool deck everything outside my house.,

everytime i trimmed my plants or trees and if something fell in their yard i tried everything to clean it by using my rake while im sitting on top of the fence they do see me cleaning it .
Everytime im doing something or somebody is working at my house they want to know.It likes i hired a guy to put motion light on jmy backyard suddenly im seeing them by my yard and when i walked out they walked away and i was wondering why till i put two things together.And when i confront her cuz i already see the damages on my yard and she told me that i was spying on them and i was surprised cuz i guess that one neighbor said i put camera which i only put motion light ..

But now i do have camera now around my house but they are still doing it.

cubsfan, good for you! Second bit of advice: Don't let up! Keep the pressure on or your gains could be lost. I can see that happening around me. I've been busy, have let issues ride and the crummy 'neighbors' are taking advantage of that. I have to take time and get back to business or they'll think I don't care and they have free rein to junk it up. I'm happy for you.

Blackcadillac, maybe you would get more responses if you posted a separate thread.

I'm sorry that you are going through this. It sounds very perplexing, like there is something missing from the story that would explain it. You sound perplexed that you don't understand why neighbors are doing this.

The one thing I would say is that if you have a camera that is actually catching neighbors on your property causing damage, the point of having it is to bring it to authorities to prove they are doing it and some action can be taken. Have you tried to do that?

If you have been living there for 20 years and these neighbors are new neighbors, I would say find someone to help you stick up for yourself. Maybe the local police department, if they are supportive of your situation.

A local hoarder that I am friendly with finally got the message after several years, not months, of neighbours pressuring the town authorities. 5 men for 10 full days and 6 dumpsters a day later the place started to look cleaned up. This is in a very desirable neighbourhood, he inherited the place from his parents over 20 years ago and I believe he is on a small monthly stipend controlled by an executor as well as a disability. This property is close to 1 full acre. Hoarding is a disease. He also has a learning disability. Now there never was an issue of drug dealing as your neighbours appear to be.

I saw him the other day and he is having a very tough time dealing with this. He has been physically ill over this, it's really sad to see him suffering. He was actually ordered to paint the peeling siding according to him, doubtful that this was in the order to comply. He will most likely loose his home as he can not afford to pay the town the bill for a weeks worth of labour and tipping fees at the town dump. Tipping or dumping fees alone are said to be in the thousands alone after he gets credit for the scrap price for metal. We are also taking about 400 manhours at about $40.00 per man hour minimally. This will be close to $20,000 added to his tax roll.

We have to have empathy for those that hoard. He couldn't afford the paint so we all passed the hat for materials and some of the neighbours that initially complained all got together and painted the place with him in a few days. I don't expect the place to look like this in a year or he may have lost his family home by then.

Your situation does seem to be different, as well as Caddilac lady. Please look at the situation not just as someone who is a slob or a "loser" as someone here called the neighbour but as someone who is disabled as well as having a real disease.