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Litter Box Aversion: Is it Medical or Behavioral?

When a cat eliminates outside of the litter box it’s probably the most frustrating behavior a cat parent ever has to cope with. All of a sudden, the cat who never caused any problems has suddenly started viewing the dining room carpet or living room sofa as makeshift litter boxes. Plastic coverings start making their way onto the sofa, the dining room becomes off limits, the box is cleaned to perfection and the cat parent starts looking at the beloved family cat as if he has become a total stranger. urinating outside of the litter box

When a cat eliminates outside of the box he isn’t being spiteful, stupid or willfully disobedient. He is trying to solve a problem. It may not make sense to you but it’s normal behavior for the cat. For some reason he feels he can’t use the box. Your job as the one with the bigger brain is to figure out why.

Surprisingly, in many cases, litter box aversion has an underlying medical cause. It could be feline lower urinary tract disease (FLUTD), the start of renal failure, diabetes, IBD, constipation, diarrhea,  or a number of other medically-related issues. Very often, what happens is that the cat associates the pain he feels with the box itself. He thinks if he eliminates somewhere else it won’t hurt so much. In the case of urinary issues, he may try to retain the urine as long as possible because it hurts too much to pee. When his bladder reaches maximum capacity the cat may not be close enough to the box to get there in time. With some urinary problems the accumulation of any amount of urine in the bladder can cause pain so kitty will pee in small drops throughout the house. And, if you see traces of blood in the urine (either on the carpet or in the litter box), then you know there’s definitely something going on that needs immediate medical attention.

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When it comes to leaving fecal deposits outside of the box, the cat may by experiencing painful stomach cramping due to gas accumulation and feels the need to try to eliminate wherever he is at the moment. Inflammatory Bowel Disease is one condition that can commonly result in kitty having to eliminate frequently due to cramping and pain.

litter box problems

No matter how convinced you are that a litter box problemis behavioral, don’t overlook that all-important trip to the veterinarian to rule out any underlying medical cause. If you simply assume it’s behavioral, you may cause your cat to suffer needlessly.

Any change in your cat’s behavior, litter box habits or eating/drinking habits should be viewed as a potential medical red flag. Always have your cat checked by the veterinarian as soon as you notice a change.

Some Signs of Potential Problems

increased or decreased urination

elimination outside of the litter box

frequent trips to the litter box

crying or straining while in the litter box

voiding only small amounts of urine

change in urine color

change in urine odor

traces of blood in urine

painful abdomen

distended abdomen

Change in fecal color

Change in fecal odor



blood in feces

Mucus in feces

Excessive gas

weight loss



change in appetite

change in water consumption

inability to urinate (this is an absolute EMERGENCY)

frequent licking of genital area


ammonia odor to the breath


exxcessive vocalization


Note: This article is not intended as a medical diagnosis. If you notice a change in your cat’s litter box habits, contact your veterinarian.

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Pam is unable to respond to questions or remarks posted in the comment section. If you have a question about cat behavior, you can find many answers in the articles Pam writes for the website as well as in her best-selling books.