Kids won't stop whining about dogs - bug

[Aethuviel]

For a while now, every time I come home, one of the children will say "I didn't know you had a dog! Can I keep him?"
Now, the thing is - I DON'T HAVE A DOG. Never did.

I remember that shortly before this happened, I met one of many random strays out in the wilds. If I remember correctly, I killed it. I never spoke to/activated it, and if you leave your dog for three days in a spot, it will disappear anyway.

It's been weeks, and every. single. time. I come home, the kids keep asking about the dog.
I even tried to adopt another random stray so I can get rid of it and maybe "fix" the game that way, but it couldn't be spoken to.

[Aethuviel]

Yep... now I tried to buy the dog in Markarth just to check, and he says I already have an animal with me. But it doesn't exist!

I want my kids to bring home interesting pets, not whine about non-existing dogs.

[Aethuviel]

Another test: I could adopt Meeko, and let the kids keep him. Strange. I had never interacted with Meeko before on this character.

[Aethuviel]

Another test, and you're gonna hate me for this: I went to Meeko's shack, adopted him, killed him on the spot, then went back home. The kids are back to normal.
Huh. Seems the bug was about Meeko, since I can't adopt other dogs.

[Aethuviel]

It happened again. Same playthrough.

Last time I saw a stray dog was days ago, and it was dead when I found it. I have never recruited a dog. Kid asks about dog, even though she already has a fox.

I try adopting and killing Meeko. She still asks for the dog.
I try asking Banning about buying a dog - unlike last time, this works. I can buy the dog, kill it, and the kids still ask.
I try simply saying "no", leaving, waiting 24 hours, and... the kids still ask for my ******* dog.

Help.