I've got a 13 year old female cat, who is loving and soft and spends most time sleeping upstairs.
However, she is extremely territorial and if she sees another cat in our garden through the patio doors she will growl. If you happen to be in the same room she will see us as the threat and attack us. It happens a couple of times a year and is always related to another cat being in the vicinity. She will also poo in the house to mark her territory after an altercation.
Recently we've had a cat come in the garden a lot and it's stressful. I try to keep the door shut so she can't get in the room to see the garden. She has a catflap and comes and goes from another part of the house and we've never really had any problems from there. It's always related to seeing cats in the garden. I've got young children and I cannot leave them alone with her in that room in case another cat comes in the garden. It's impossible to keep the door shut on our main family living space but I don't know what to do.
I've spoken to the vets, they ran lots of tests to check there was no underlying health issues causing aggression. They gave her gabapentin for a short term solution but I can't keep her sedated long term. They're are such isolated incidents, we know the trigger but we can't predict when other cats will be in the vicinity.
I've tried herbal supplement recommended by the vet and pheromone diffusers. I'm just really worried about the transferred aggression being aimed at the kids.
Any suggestions, she is a much loved family cat. But we live on egg shells!