Calming aggressiveness of dominant cat litter mate

Dear Cathy: Our two cats are 2-year-old litter mates. Over the past couple of months, Rebecca has gotten aggressive, jumping at Marcy (who has a calmer personality) in ways that are fiercer than play fights. This looks like repeated attempts to establish dominance. If Marcy curls up in my lap or my husband’s lap, Rebecca will attack her for sure.

They get along most of the time, but no longer curl up together or groom each other. On occasion, Marcy will initiate a game of chase, but she is starting to slink around and hide from Rebecca.

They are regularly left alone in the house for some hours, and we don’t let them in our room at night. They don’t go outside and are not as interested in toys like when they were kittens, so sometimes they seem bored. We try to maintain balance by petting and praising both equally.

What else can we do to keep Marcy from getting beat up? — Jenna, Roanoke, Virginia

Dear Marcy: Litter mates don’t always get along as much as we think they would. They establish a very early hierarchy that stays with them throughout their lives. If one cat is always more dominant, the other cat never gets a chance to come out of her shell, so to speak.

Here are a few things to try: First, get feline pheromone plug-ins for your home and pheromone collars for both cats — or at least for Rebecca if that’s all you can afford. Feline pheromones will remind them of when they were kittens and can help restore some balance and reduce skirmishes. Spray feline pheromones where they sleep, on your laps, and on the couches, or other spots around the house, to create more calm.

Second, make sure Rebecca is not seeing a stray cat or other animal outside that she can’t get to. Cats can have misplaced aggression, which occurs when they see another animal they cannot reach and they take out their frustration on the closest person or animals inside.

Finally, get a “Pet Corrector” — a small can of compressed air that provides a “Shhh” sound to interrupt unwanted behaviors. Spray this whenever Rebecca goes after Marcy. Marcy may also startle, but hopefully you only have to use it a few times to convince Rebecca to back off.

Finally, play with them separately several times for five to 10 minutes at a time. Tired cats are more likely to sleep than fight.