Hello I am after some advice, although I am pretty sure I know the answer, I'm just hoping to avoid rehoming.
This may be a bit long. So I have a nearly 2 year old female and a 9 month old male both neutered. Had them both since kitten so have been together now for 7 months.
There has been no changes, they are indoor but with lots of stimulation and I have a calcony (catio but enclosed balcony) no stress that I can recall, no litter or territorial issues as they have lots of space both shared and isolated.
First my female cat did not like new male at all, I did all of the right introduction as in separated from the beginning, scent swapping, feeding either side of the door etc etc I did this for about a month and eventually they got curious and see each other. Female cat would hiss and run away.
Slowly, they were completely integrated but have NEVER got along. Male cat has now become quite dominant and pretty sure he thinks he is boss and will constantly, and I'm not exaggerating, pounce on her. Sometimes it is playful but always turns into real fighting.
It's gotten to the point now that they simply cannot be together even for 5 mins without fighting. I've tried feliway, diffusers, all the plug ins, I've done shared play and shared positive experiences. I've had them both checked at the vet and nothing is standing out as wrong.
The strangest thing is though, they can have rare moments where they have laid together or bumped noses and greeted each other but this is so rare that its kind of irrelevant now.
It's come to a bit of a head this week where I noticed male has a wound on his head, I presume from the fighting, which means they are meaning to hurt each other. I don't know what to do because even rehoming I couldn't choose which one as I don't want to rehome either of them but this isn't enjoyable or peaceful for me or the cats.
They both have separate everything, 3 litter trays all in separate 'safe' spots. They both get the same amount of play and love. I originally thought male was the aggressor and tbh still do but now female is just as bad.
Everyone irl said to me, they will be best friends in a week and cuddling up to each other, it's been 7 months and they don't even tolerate each other.
Any advice please?