Strange cat behavior shes been rolling around the floor

I don't think my cats feeling well. She's been rolling around on the floor wildly and then putting her butt up in the air as if in heat, but she produces an angry, long and loud growl (different than the ones she normally makes). Besides that, she appears normal--but she keeps repeating this process and it's freaking me out.

She also snorts a lot and almost sounds as if she needs to vomit. What's wrong with her?

Answer from Kate
From your description I would still say that it sounds like she is displaying signs of being in heat.

Their behavior can change quite dramatically change and seem very unusual.

Have you not considered having her spayed to make her a happier more contented cat who would not have to go through these symptoms every 3 weeks? Their are also other health benefits for your cat too.

i have some pages about this which you may find of further interest here

https://www.our-happy-cat.com/neuter.html

best wishes Kate

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