Chris H. has a problem between a pair of outdoor cats. Chris writes:
Chris, any time there is a change in litter box habits, there is a cause. Something has changed in Clyde's world and has made him react this way. Our first guess is that the big change was the addition of Miss Kitty to the family, but it could be other things as well. Think long and hard about any changes that might have affected Clyde. Has his litter been switched? Is something new being stored in his shed? Has the shed been rearranged? Are new people coming into his territory? Are neighbor cats spraying in the area? Has his bedding been changed? While you consider these things, it would be wise to take Clyde in to the veterinarian for a checkup just to make sure there are no medical reasons for his behavior.
Cats generally cover their poop so as not to alert both predators and prey to their presence. However, some cats mark their territory with their feces; a process called middening. If Clyde is leaving his poop uncovered out in the open, he's trying to make himself feel more secure in his territory. If he also poops where Miss Kitty's scent is the strongest - her bed - he may be trying to make it clear to her that the shed is all his and he doesn't want to share it.
We would be remiss if we didn't mention the fact that outdoor cats encounter other animals who may be a threat to them on a regular basis. Keeping the cats indoors would definitely insure longer, less stressful lives for them both if they would tolerate the transition. That said, we do have some suggestions to help you ease Clyde and Miss Kitty past this crisis.
The first step should be to replace any bedding in Miss Kitty's house and clean it with a good enzymatic cleaner. Normal household products will not work against cat urine and feces smells. Once the house is clean and Miss Kitty's bedding has been laundered or replaced, you should relocate both cats' houses outside the shed. The further apart they are, the better. This will give each cat a chance to establish his or her own territory.
It's likely that the shed has become the point of conflict between the two cats. While it's easy to blame Clyde because you see the evidence of his handiwork, don't forget that Miss Kitty could be leaving scent marks on his things as well. The key to helping them to get along is to make sure they each have equal and separate sets of resources. At present, the shed itself is a valued territory that may have become a point of contention between your two feline friends. Cats usually choose to avoid conflict, and Clyde may have been doing so since you introduced Miss Kitty, but at a certain point he's decided to make his true feelings crystal clear.
Make sure that there's nothing objectionable about the litter box that Clyde uses. It should be in an area where Clyde won't feel trapped and it should not be covered. You can see our litter box and litter recommendations here.
There are a couple of additional things you can do to help. One is to spray Clyde's bedding and house with a synthetic feline hormone like Feliway. Clyde would have to be very stressed out to act as he has, so this could help ease those feelings, albeit temporarily.
The second thing would be to check the shed inside and out for other feline markings. If Clyde's territory has been challenged by another cat outside the family, he might react this way to make himself feel better. You can see markings with an inexpensive black light flashlight. Cat spray and urine will glow in the blacklight. If you find markings, clean them with the enzymatic cleaner and that should also help ease Clyde's bad feelings.
In the end, it will be up to you to make sure each cat feels loved separately. We often imagine the addition of a new cat will make our present pet happier, but that's not always the case. Sometimes the new cat's presence complicates a simple situation and creates new boundary issues. In many cases, the addition of a third cat can actually solve the problem IF that cat's personality is well chosen. See this post for more on the subject.
Chris, clearly you and your family care for both cats and want to help them thrive. We think you just need to look at their world through their eyes and you'll soon be able to solve their problem. We wish you all the best!