Hey guys!

One of my kittens had unfortunately fallen from a window while we were away from home yesterday. Eventually, within the same day/night, one of my neighbors posted online that they found a cat, and it was it.

Now he’s finally and thankfully back at home, but my other cat, its sister, is quite hostile towards him, hissing and slapping.

My neighbor had another cat and also a dog, can this be related? Can he be bringing “their smell” and now my other cat senses it? What can we do to solve it?

Thanks in advance!