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Are Outdoor Cats Stressing Your Indoor Cats? Here’s What to Do

Neighbors' cats as well as strays and ferals can disrupt your indoor cat's sense of well-being; here are things you can do that won't harm any felines.

Marilyn Krieger  |  Apr 8th 2016


You’ve probably heard the reasons why cats shouldn’t be allowed to roam outside. Most of the discussions concentrate on the health and safety of the wanderers. Not enough attention is placed on the impact the unwanted visitors can have on resident kitties who live indoors.

The sights and smells of the feline trespassers patrolling and those who camp out around homes can cause serious issues for indoor kitties and their people. Buddies can become sworn enemies, many unhappy cats express their displeasure by spraying or eliminating outside litter boxes. Others respond through redirected aggression — venting their frustration onto whoever happens to be near them.

Neighborhood cats can cause redirected aggression

Neighborhood cats can cause redirected aggression. Photo by Shutterstock

Chances are you’ve seen them — and if they spray, you’ve smelled them. They might live next door or they might be feral. There is always the chance that they are lost, and somewhere people are frantically trying to locate them. Feral or owned, they often wreak havoc on households.

Although frustrating and often heart-breaking (it’s terrible when kitties who’ve been best buds are at war with each other), you can do something about the situation without harming the perpetrators. Here are some actions you can take to bring peace and harmony back to your household:

Remove the reasons for the visits

In order to persuade the kitties to move on, make your property unpleasant while removing the reasons they visit. If you have bird feeders, either stop feeding the birds or relocate the feeders to areas that are not viewable from inside your home. Although you might enjoy fraternizing with the neighborhood cats, don’t encourage them to stay by interacting with them around your home.

Feed the neighborhood cats where your cats can't see them

Feed the neighborhood cats where your cats can’t see them. Photo by Shutterstock

Use deterrents

Persuade the intruders to move on by placing safe deterrents around your property. Fences often do double duty. In addition to delineating property, they sometimes function as thoroughfares for kitties on patrol. Discourage the practice by making fences difficult to navigate by attaching bird spikes to the tops. Additionally, dissuade visitors by mounting motion sensitive devices outside that emit ultrasonic noises. Be mindful about them — they can also agitate your cats and dogs. Lemon and other noxious products placed around the perimeter of the property or on top of fences can also help deter the trespassers. Refresh them periodically, especially after it rains. Other effective deterrents include motion sensitive devices that spray water toward the offenders.

Cat using a fence as a highway

Cats often use fences as highways. Photo by Shutterstock

Talk to the neighbors

The unwelcome feline visitors might live next door or down the road. If you know where they live, encourage their owners to either keep them indoors or to build enclosures for them. Freshly baked cookies or muffins can be very persuasive. Sometimes nothing works, but it’s worth trying.

Ask your neighbors to keep their cats safe inside

Ask your neighbors to keep their cats safe inside. Photo by Shutterstock

Trap, neuter, and release feral cats

Contact a rescue group or a no-kill shelter. Such establishments should either provide you traps along with instructions on their use or come to your location and trap and neuter the cats.

Clean up urine outside

Some felines, especially those who are intact, claim your home as their territory by spraying around it. Along with trees and bushes, they may target doors and windows. Resident kitties, smelling the noxious scent, understandably become agitated. It is important to eliminate the odors by cleaning the sprayed areas with an effective enzyme cleaner. It might take a few applications until the scent is gone.

Neighborhood cats often spray to mark territory

Neighborhood cats often spray to mark territory. Photo by Shutterstock

Clean up urine inside your home

Outdoor cats can trigger indoor kitties to mark their territories and communicate their displeasure about the other cats’ presence. The residents might spray or urinate outside their litter boxes. Don’t punish or yell at them, they aren’t being bad. Instead, clean up the area, using an effective enzyme cleaner. Like with the outside spraying areas, t might take a few applications until the scent is gone. Because most enzyme cleaners work as they dry, allow the product to dry naturally.

Control the views and limit areas

The sight of the intruders can be enough to agitate and cause problems for the residents. Block the view by covering the windows with film, fabric, or paper so that your kitties cannot see the other cats. After the outsiders no longer visit, gradually uncover the windows.

Neighborhood cat looking through a window

Neighborhood cat looking through a window. Photo by Shutterstock

Separate and reintroduce warring cats

Cats in the ‘hood cruising around homes often cause indoor kitties to fight each other. This serious aggression, called redirected aggression, occurs when the cats, unable to reach the source of their angst, vent their frustration onto the nearest animal — often their best friend.

As soon as there are problems, separate the cats, placing them in different rooms. Your safety is a priority. Don’t use your hands or body to separate them; you might become the next victim of redirected aggression. After the kitties have calmed down, start gradually reintroducing them to each other. It might take weeks or months until they can peacefully be around each other again.

Gradually re-introduce cats to each other

Gradually reintroduce cats to each other. Photo by Marilyn Krieger

Think twice before letting cats roam the neighborhood. In addition to the dangers they encounter outdoors, cats who wander the ‘hood can cause serious issues for nearby indoor kitties and their owners. Their presence can cause resident kitties to become agitated and stressed, sometimes spraying, eliminating outside their litter box, or becoming aggressive.

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Do you have a cat behavior question for Marilyn? Ask our behaviorist in the comments below and you might be featured in an upcoming column. If you suspect a behavioral problem, always rule out any possible medical issues that may be causing the behavior by first having your cat examined by a veterinarian.

Marilyn, a certified cat behavior consultant, owner of The Cat Coach, LLC, solves cat behavior problems nationally and internationally through on site and Skype consultations. She uses positive reinforcement, including environmental changes, clicker training and other behavior modification techniques.

She is also an award winning author. Her book Naughty No More! focuses on solving cat behavior problems through clicker training and other positive reinforcement methods. Marilyn is big on education — she feels it is important for cat parents to know the reasons behind their cat’s behaviors.

She is a frequent guest on television and radio, answering cat behavior questions and helping people understand their cats.