Where do released for adoption pets go?

No, the puppies aren't corrupt. They are culled.
Because pets who are put up for adoption go to the Other Households section, they can get culled aka deleted by game to make room for newly generated sims.

There is no culling in my game because of mcc. If they are culled, how can they stay in my other households shouldn´t they vanish? And the two ones from today, they didn´t show up under my other households and they make problems when I try to adopt them with another family. The adopt service came and nothing happens. No problem with the other available pets. Tested without mods too. There must be a problem with the released for adoption option...

Any pet or child taken whether it is for adoption or because it was mistreated gets their files removed - so they are technically gone forever. The only game that actually put pets or kids taken or adopted that didn't get the files destroyed was Sims 2. Sims 2 actually put kids and pets in the adoption pool - Sims 1,3, and 4 destroys the files.

In Sims 3 you could avoid the destruction of the pets by doing a private adoption though. Just don't call an adoption agency and give the pets to them or they'll be gone.

Than release for adoption didn´t make any sense for me. Since the start from C&D I can release pets and, until now, and they show up in the adoption window for other families, with and without mods.
They say that it should work like that at the release from C&D. Something has changed in one of the last patches that the files are corrupted.

Or did I miss understood the whole adoption thing or is it simply one of the 1000 existing bugs?

It's been like that since Sims 4 came out from my understanding. As I saw simmers who had babies taken away and they went looking for the babies - no where to be found. The alien babies when you send the back to their so-called alien world - they will never be found again because the files get destroyed. One of the modders - I forget who it is but it was a modder that was posting about stuff he saw added to files on coming packs - said the files get destroyed with the babies and kids that get taken away, returned to their world, or given up for adoption. Then when Cats and dogs came out - said it was the same way for them. The only pets that don't get their files destroyed - at least not right away anyway - is the runaways. They will stay around for a bit as long as you can call them back home - but the game will eventually cull them as well.

I understand it is by design of Sims 1,3, and 4, not something new.
Because of it - in Sims 3 if I had to give up any pets for adoption - I always did the private adoptions so they were not removed from the game. Granted I did not breed most of my pets unless I had sims family members to give them to in other households. It just does not sit right with me - pixels or not - they get destroyed. I find it creepy. I have not breed any Sims 4 cats or dogs and I just take in the strays. That's how much it creeps me out. LOL.

The game is designed to cull them - so if your mod stops the culling - part of their files are destroyed - the mod is creating corruption if it is stopping the game from doing what it is designed to do. The only thing the game programming accepts as unculled without some file destruction is us favoriting sims or households.

eta - Here's a thread from back in November - same issue - https://forums.thesims.com/en_us/discussion/930021/giving-up-a-pet-for-adoption

It's been like that since the beginning - by design.

@Writin_Reg Ok, than I really miss understood how adoption works in Sims 4. Never mind, when it´s like that I need to change my handling.
Tested it again without mods, only SimsInfo, they show up in the adoption window and in SimsInfo with a different ID.
Adoption in another household didn´t work right after changing the household,
changing back to the first household it does, but the pet has a third different ID

"Rass;c-16669115" wrote:
@Writin_Reg Ok, than I really miss understood how adoption works in Sims 4. Never mind, when it´s like that I need to change my handling.
Tested it again without mods, only SimsInfo, they show up in the adoption window and in SimsInfo with a different ID.
Adoption in another household didn´t work right after changing the household,
changing back to the first household it does, but the pet has a third different ID

Those new versions are just a clone - and in this game clone characters are just in appearance - their files will be new and different than the original as the minute that pet leaves you lot it seems to just get cloned with the original destroyed. So it sort of fooled us to start with thinking it was the same - but since then have learned it is not.

I really, really wished they went back to the Sims 2 way of handling pets and kids - It really freaks me out destroying them like that even if they are just pixels. (My husband thinks I am silly over it all - but I can't help how I feel. of course hubby is not a simmer - so I can't expect him to "get it". LOL)