Cat at Litterbox

Q. One of my cats attacks the other in the litterbox. Now I'm finding cat mess in the spare bedroom. How can I stop this?

A. Although many cats will happily share a litterbox, it’s not at all uncommon for cats who otherwise get along to draw the line at sharing a potty. While the problem doesn’t always involve hisses and attacks, it usually does involve the use of alternative bathroom facilities that the cat owners rarely like.

The first rule of solving any behavior problem is to make sure it is not a medical problem. Take your cats in for complete veterinary checkups. If either of your cats is ill, you won't get very far with retraining efforts. Once you get the all clear, here are your next steps:

Add litterboxes in additional locations. The minimum number of litterboxes recommended by many behaviorists is one per cat, plus one additional box. Since your cats have known territorial issues, I’d have at least two boxes per cat, in at least two locations in different parts of the house. Remember, too, that locations have to be “safe” in the mind of a cat. That means quiet, sheltered and with the ability for a cat to see what’s coming at him. No one wants to be ambushed while in such a vulnerable position!

Retrain the cat who has stopped using the box. Clean any areas where mistakes were made with an enzymatic pet mess cleaner (your veterinarian can recommend a good one). Set up a “safe room” — possibly that spare bedroom, once it's thoroughly cleaned, or a bathroom with rugs that can be washed — with the litterboxes, food and water, a bed and a scratching post or cat tree. For the time being, make it off-limits to the other cat. Keep your outside-the-box cat there for a few days (up to a couple weeks) with frequent visits from you until you see the routine use of the litterbox. Then open the door and allow the cats to reacquaint on their own time, but don’t force them.

You can try to bring down the stress levels throughout the home with the use of synthetic pheromones from your veterinarian or pet-supply retailer. These substances mimic those produced by a mother cat to soothe her babies, and they really work to calm some cats.

If you’re still having problems after separating the cats, ask your veterinarian for a referral to a behaviorist for help.