I read this a LONG time ago, so I don't much about it. I apologize in advance 😅 3u6i3r

I know the MC had a dog that ed away, and so he picked up a white cat that reminded him of his white dog. But, I think the cat was actually tiger?? And he turns into a human man. But, I think there was a twist where the dog wasn't actually a dog, it was the cat?? And MC's memories had been altered? Again, I apologize, this is the most I can .

Could it be Tiger Lily? It’s been a while since I read it so I don’t everything but it has elements of what you described.

https://mangaupdates.telechargertorrent.org/series/odxfzlw/tiger-lily

No, it's not that one. Thank you for trying, though!