Q: My fiancé and I have no idea what to do. We are at our breaking point almost with our cat! He first caught a mouse a couple weeks ago and my fiancé said he was growling and making weird noises. Fast forward to this week and he will not stop running around/into things and his aggression toward our other cat has gotten so bad that she’s terrified! Please help us; we have no idea what to do! —E. F., Cyberspace
A: I wish I could snap my fingers and answer, but I don’t have enough information, particularly providing your cat’s history and lifestyle. And, the biggest question of all, is your cat an indoor/outdoor cat who snatched the mouse outside? Or, did kitty find the mouse inside?
If the cat is an indoor/outdoor cat and has not demonstrated this behavior previously but has captured previous mice, I wonder why this behavior has occurred now? The answer to that could be medical. See your veterinarian, and bring a video of the behavior. Among other concerns, your veterinarian should rule out parasites and pain as causes.
If your cat is inside only and snatched the unfortunate rodent indoors, I suggest your cat was over-stimulated, and his hormones skyrocketed beyond control. That is not your cat’s fault.
I am concerned about the relationship between cats. It’s possible the cat who caught the mouse redirected aggression to the other cat, who was previously this cat’s pal. Or, maybe they’ve never gotten along. Either way, that information matters.
A cat who has hormones that have spiraled out of control can commonly take three days to return to normal or longer, especially if the object of the cat’s unfair aggression remains available. And that could explain your cat’s continued aggression.
There have been instances of changes in a cat’s health prompting aggression toward other cats. Your cat may know something you don’t.
If there’s still an issue between the cats, definitely separate them until you figure things out. And keep them separated until you receive professional help from a certified cat behavior consultant or a veterinary behaviorist. One excellent resource is Certified Cat Behavior Consultant Pam Johnson-Bennett’s book, Cat vs. Cat.
If this aggressive behavior frequently occurs after the cat has gone outdoors and then returns inside, consider keeping the cat indoors all the time. In order to do this, you need to really enrich the indoor environment. For starters, hide teats around the house, and your cat may be a purrfect candidate for a feeding system called Doc & Phoebe’s (formerly called No Bowl). The idea is to hide kibble inside food dispensing mice-like objects. The cats need to search (hunt) for them, and then manipulate and pounce in order to get the kibble out of the individual mice-like objects.
(If you order, indicate CATSWINN as a discount code in the online store at checkout to support funding the nonprofit Winn Feline Foundation’s cat health studies.)
Of course, also offer your cats vertical space, hiding places (where they can get away from each other), and rotate toys. There’s no downside to enriching the environment.
I realize taking a cat that’s lived life outdoors for many years and transitioning to indoor-only may be challenging. Of course, that transition doesn’t need to occur overnight.