Ask neighbors or go to city hall and check in with officials. Fences can be an expensive option, but might be worth it if the dogs are not easily deterred.
[header] How to discourage dogs from pooping in your garden [title] Put up a fence. [step] Perhaps the most obvious solution, if not the most cost effective, is simply fencing in your garden to keep dogs out. [substeps] Make sure your fence is in line with local property laws.