Hey Cherry, what about this form,
1- You have a cat, don't you?
2-You do have a cat, haven't you?
Some of what follows has already been said, but as the thread has re-started , I'll try to clarify.
1.
You have a cat, don't you? - Common in AmE
1a.
You have a cat, haven't you? Normal for some speakers of BrE.
1b.
You've got a cat, haven't you? Common in spoken BrE.
2.
You do have a cat, haven't you? Unnatural in both dialects. It's the emphatic 'do' that will be questioned in the tag.
2b.
You do have a cat, don't you? Natural in both dialects.
3.
You got a cat, don't you? Non-standard. I believe it's used by some AmE speakers.
4.
You have had/owned a cat, haven't you? The auxiliary 'have' in the first sentence, part of the present perfect, is obligatory in the tag in both dialects.
