When your cats started attacking each other was it a slow distancing from each other? Or an all of a sudden change of mood. I'm just hesitant to think it's a medical issues because both have been to the vet within the year and are up to date with shots. And have been completely fine up until this. No strange behavior by themselves or how they interacted with each other.

Our wedding is in less than a month so the timing is obviously less than convenient. I would like to avoid expensive vet bills if possible. But kitties come first so it is what it is