How can I stop the dog from next door peeing on my walls?

Have you talked to your next door neighbor? They need to be made aware and become responsible pet owners who respect your property.

Last year we had a similar situation where the neighbor was allowing her dog, on a leash mind you, come over to the side of our driveway and have her dog poop, not remove it if course. I scooped it up on a shovel and left it on her doorstep and path to her car. She got the point.

Best to you.

Is their dog neutered? Is your dog spayed? they both really should be fixed. When you watch their dog at your place you need to put him on a leash when he comes in your house so he cannot do whatever he wants. Train him that it is not acceptable.

https://www.dogchatforum.com/dog-marking-inside.htm

You can try Bitter Apple spray, but there are no guarantees. We rescued a male neutered dog last October. We are still trying to break him of random marking in the house. Most recently, he "marked" a blue ray player. Guess my ex hubby needs to get a new one. Being neutered means nothing, as any male dog I know still marks territory. Here are some things you can try.

https://www.adoptapet.com/blog/stop-your-dogs-territorial-marking-inside/

https://www.akc.org/expert-advice/training/curbing-marking/

https://www.whole-dog-journal.com/issues/20_4/features/Stop-Urine-Marking-in-the-House_21625-1.html