Cat fights

Question
My two female cats, 7 and 8 years old, sisters, used to
cuddle and now they can't be close to each other without
hissing and the fur flies! It's been over a year with this
troublesome behaviour. I'm at a loss and don't know what to
do! One is spayed, one is not. They have always been in the
house and have never been outside.They only stop if I am
there and tell them "no." But I can see the fur around and
it happens all the time! Help!

Answer
This typically happens when something changes in the environment and they don't know how to adjust. Which one usually starts it? Think back to when it started and try to remember what could have happened to trigger the change. I'm guess that the one that's not spayed is the one starting it, but that's just a guess. Do they still lay together, eat together and all that fun stuff? Do they use the same litter box? One thing you could try is giving them separate areas to call their own. This is probably going to be a trial and error situation to find out what exactly is triggering and what it's going to take to fix it.