My daughter has three cats who live indoors with daughter and boyfriend of 8 years. Their first cat, Gidget, is a five year old spayed female. She was queen of their home until two 8 week old kittens joined their household. One is a neutered male and the other is a spayed female. They are now 18 months old. Gidget has slowly warmed up to the two interlopers, but recently the three of them have started fighting with each other. Whenever they cross paths in the house, they seem startled and start hissing, growling, swatting and chasing each other. The two females are most often involved in the fighting.
The house has been peaceful for months until last week. Why are they fighting and what can be done to stop this behavior? Is this teenage irritability? Is the younger female trying to move up the dominance chain? Any advice would be appreciated!!