- Old dogs, New Tricks – when you get a dog at a year old, there's probably a lot of prior (mis)training to overcome and deprogram, and
- These Things Take Time (The 4 T's) – between the established disposition of your pup, and the general anxiety of a new place to call home, it's probably going to take a lot longer to "cure" him completely.
- "I pee because you're the boss!" – Submissive urination is real, and is often meant to show respect for authority.
You mentioned adopting, but didn't say from where… Assuming for a moment that you, or other interested readers with similar issues, picked up a rescue/shelter animal, it's possible that any of the following have happened:
- Prior "failed" adoption(s)
- Brief foster periods
- Acclimation to the organized chaos of shelter life, and the freedom to pee on concrete floors on a whim with no ill repercussions
Regardless of the origin, the solution is very much like curing "accidents" in toddlers/preschoolers:
- close monitoring and possible rationing of liquid intake
- regular walk times and intervals
- praise for properly expressing the need to pee before it happens
That, combined with a more general program to help establish the new dog's place in the existing pack hierarchy, as well as give him reassurance that he's "home to stay", should help reduce/eliminate the problem over time.
How long that period is, however, will vary quite a bit based on the dog's personal history, and your general patience level. If at all possible, focusing on rewarding good behaviors over punishing bad ones (even those of the other dogs) until the problem is under better control, will hopefully shorten it to just another month or two. 😉
Worst case scenario, you can look into diapering the animal (this is dangerous – some will hate it, and "get" that they need to stop peeing in order to be free, but others will just appreciate not having to care about letting loose on a whim), or even a prescription/surgical solution (ask you vet, but as I recall, these are pretty spendy), and of course you can also just keep him in semi-isolation (kitchen only while indoors).
Whatever you do, the keys are to show love early and often, and try to make him understand that the peeing doesn't make you happy without being punitive. At their hearts, dogs just want to make the leader (you) happy, and will usually go beyond all reason to do so. But they have a funny way of interpreting even negative attention as a good thing, so the messaging needs to be consistent and careful.