Sisters Suddenly Fighting

Question
Hi Ali,

I have two female torti's that I adopted about 4.5 years ago.  I was told they were litter mates and they have always been close to one another.  They would sleep curled up next to each other, eat out of the same dish, etc.  Last year when one of them, Zoe, had a peeing problem it would upset the other, Franny, because she Zoe was upset.  The point is they are (or were) very close.

They are indoor cats and yesterday I left the door open just a crack to get some fresh air in the house.  Franny would slip outside for a minute or two and then come back in.  This went on for about 3 hours.  Then the last time she came back in Zoe hissed at her, growled, spit, etc.  Franny was a little startled but when it didn't stop she responded in kind.  The level of aggression increased throughout the afternoon then subsided somewhat during the night and has begun again.

My thought is that being outside Franny somehow smells different to Zoe, but there have been occasions when Zoe has gotten out for hours at a time and Franny never got so aggressive.

Also, there appears to be some jealousy over me developing.  This is really sad to watch as they have always been so close and sweet with one another.  Any explanations and suggestions would be greatly appreciated.

Thanks, Aimee

Answer
Aimee,

The first recommendation that I have when you notice a substantial change in behavior is to see your vet and rule out any medical causes. It may be that Zoe is reacting to a different smell than she is used to. I am somewhat concerned that this has started so quickly. I have two torties as well who aren't litter mates and recently my older tortie spent almost a week in the hospital. I was prepared for an issue when she came home partially because she smelled like the vet, unfamiliar people and animals and partially because there has always been a bit of "sibling" rivalry between the two torties...I was pleasantly surprised to note that the my two younger cats were scratching and meowing at the door of my bedroom to be let in to see the kitty who had come home from the hospital. I expected fireworks when they saw each other face to face and to my complete amazement the younger tortie inspected the older one from head to toe and proceeded to wash the hospital smell off of her. It seems a little odd to me that the Zoe is reacting so extremely over short separations. It could mean that Zoe or Franny aren't feeling well. If your vet finds no medical cause for this behavior then I suggest that you try using a homeopathic remedy called Bach's Rescue Remedy which is a blend of flower essences that helps to comfort and reassure. I recommend that you use a dosage of about 8 drops in their water bowl with fresh water every morning. You can generally find Rescue Remedy in health food/natural health stores. I have had good success with using it to treat anxiety, agitation, aggression and other situations. It is not harmful to the cats, but I would like to warn you that homeopathy is a bit like peeling an onion, you peel one layer and there is another below it...I highly recommend that you seek out an appointment in your area with a holistic vet. A holistic vet uses a combination of Western medicine and complimentary techniques like homeopathy, herbal remedies, acupuncture and massage to treat a variety of conditions. I hope that this information helps. I am sorry that I wasn't able to offer a specific cause for the behavior, but there are so many possibilities. If you have any further questions or concerns, please do not hesitate to contact me again.