My cats now hate each other

Question
A few days ago both my cats, who are spayed and sisters, were laying in the window together and all of a sudden they just went at it! I think there may have been another cat outside. They started to fight, hiss, scratch and continue to fight till I was able to break them apart. It was pretty serious because one of them was bleeding form her ear. It has been about 5 days and they still hate each other and if they see each other, they hiss and I break it up before anything starts. What can I do to end this feud? I have cat sedatives that I used when I traveled with them, could I use them to make this process go smoother? Thanks for the help!!

Answer
Katie,

Unfortunately, it is quite normal.  One or the other or both may have seen a strange cat after which fight/fright/flight instincts take over and they forget who they are and that they even know each other.  My feeling about this is they need a time out in separate interior rooms away from any windows.  It usually does take about a week or two for things to calm back down again, until the next time.

Once you let them back together, they have to go back through the typical cat "getting to know you ritual" and that will take as long as it takes.  I would grit my teeth and ignore what may sound like world War III.  As long as no one draws blood, they will settle things in their own feline way! Any human interference or continued separation will only prolong any return to normalcy.

My only objection to cat sedatives, is that sometimes they do the opposite and that will certainly make matters worse.  BTW, why would you sedate your cats to travel?

Please let me know how it goes.

Best regards... Norm.