We have two six year-old female cats, named Mitsy and Kizzy, both from the same litter and adopted together from an animal rescue centre when they were three months old.
They have been indoor cats since birth, and lived happily together up until the day that Kizzy had to stay overnight at the vets. When Kizzy was brought back to the house the following day Mitsy exhibited territorial aggression as if she had never met Kizzy before. We assumed this was due to the smell of the vets and other animals and hoped this would wear off within a few hours or days once she realised that it was her sister.
That was about three months ago and the situation has not improved. Initially the vet advised us to keep them apart in separate parts of the house and to introduce them to each other one sense at a time i.e. by first exchanging their scent by sharing their bedding, food bowls, socks, towels etc., and then next a few days later by sight only e.g. by feeding at the same time either side of a glass door, and then finally by both sight and smell e.g. by opening the glass door a little at a time. During this period we used a feline pheromone diffuser and spray. However, as soon as Mitsy has sight of Kizzy she becomes territorial e.g. by staring, hissing, or standing on her back legs and pawing the glass door. We also bought a cat behaviour book and restarted the reintroduction process all over again but this also failed to work. As Kizzy is the victim, she has the run of the house with Mitsy staying mostly in one room, and once or twice a day they get to swap around, the only dividing line being the pet screen door.
Most of the time Kizzy just seems confused about all the fuss, but on one occasion she did mirror the same standing and pawing action on the other side of the door, perhaps in a defensive way. We recently installed a pet screen door in the hope that a combination of scent and smell would help, considering that Mitsy does not appear too bothered about smell, since they happily use each other’s litter trays, feeding bowls and scratching posts. We stopped using the feline pheromone diffuser and spray a few weeks ago as it was expensive and ineffective at dealing with territorial aggression.
Both cats appear to be fairly content to live this way, but with segregated areas and closed doors it’s like living in a zoo.
If you've had a similar experience and been able to solve it then please can you share your story?
Thanks.
