Summary
Inappropriate elimination is a general term used by veterinarians to describe urination and defecation that happens where it shouldn't. Cats and dogs that eliminate indoors in non-owner sanctioned locations are generally said to suffer from an "elimination disorder."
In pets, the act of urinating or defecating in unwelcome locations is generally said to emerge from either a behavioral issue, a medical issue, or (most likely) from a confluence of both. In cats, it may be better described as being primarily health-related, "bathroom"-related, or communication-related:
Feline Health
Sometimes known as "Feline Lower Urinary Tract Disease" or "Feline Idiopathic Cystitis," this common condition occurs when the feline lower urinary tract (which includes the bladder and/or urethra) becomes inflamed. Affected cats will often display their discomfort by urinating frequently in odd spots.
Urinary tract infections can cause this, too, but they're considered far less common than the above-mentioned inflammatory disease. Urolithiasis (stones in the urine, usually found in the bladder) can also lead to inappropriate elimination.
Because they lead to increased urine production, diabetes and kidney disease can lead to litterbox "misses," too.
Stool trouble may also be a problem. Constipation, diarrhea, inflammatory bowel disease and others can lead to "bad bathroom choices."
Geriatric disorders that limit their awareness of the litterbox's utility (such as dementia) and others that cause pain or reduced mobility (such as osteoarthritis) often play a role when it comes to "missing the box."
Bathroom Related
Some cats may simply be voting with their feet in an act of defiance of their current litterbox conditions. Whether it's a new litter, different cleaner, annoying cat, change in location, unwanted houseguest or a fight with a housemate, cats can be persnickety enough to act out in unwanted ways.
Communication or Behavior Related
If cats are stressed out, ill at ease, or just plain ill, they may be trying to tell you something by avoiding the litterbox and concentrating on spots they know you'll pay attention to. Some cats with elimination issues are simply trying to tell you something is wrong.
Symptoms and Identification
Urinating or defecating in atypical locations is the usual sign of inappropriate elimination. The following signs may also be in evidence:
increased frequency of elimination
increased volume (or clarity) of urine
blood in the urine or stool
change in the consistency of the feces
Determining the cause of the abnormal elimination is paramount to appropriate treatment. The following tests are typically recommended to rule out medical causes:
Urinalysis
Complete blood count (CBC)
Blood chemistry analysis
Fecal sample analysis (looking for blood, parasites, etc.)
Urine culture and sensitivity
Abdominal X-rays
Routine thyroid hormone testing
Abdominal ultrasound is sometimes employed as well, particularly if the presence of certain kinds of stones is suspected.
Empirical treatment with anti-inflammatory drugs, antibiotics and litterbox management techniques are sometimes employed by way of presumptive diagnosis.
Affected Breeds
Any breed of cat can be affected.
Treatment
The most common approach to treating cats with signs of inappropriate elimination involves the treatment of any underlying disease. But there are other steps, too:
Identifying or eliminating all stressors is a requisite step. As is correcting any outstanding litterbox issues. The following steps are typically recommended:
Keep the litterbox clean.
Use enough litterboxes (the rule of thumb is that every household needs one litterbox per 1.5 cats).
Via trial and error, make sure the litterbox's location is ideal.
Use bigger boxes if possible.
Try a cover -- or not. Some cats feel more comfortable with them -- others without.
Cats prefer clumping litters over non-clumping litters.
Cats prefer litters that are pine-scented over other aromas.
But don't change the brand of litter if your cat's already happy with her brand of litter.
Finding areas where the cat has urinated or defecated and eliminating the aroma is essential, too. The use of psychoactive medication may also be required for some cats.
Veterinary Cost
The cost of veterinary care for this condition is typically relegated to the cost of diagnosis and/or medication. Nevertheless, this can be a very expensive condition for owners whose furnishings are ultimately destroyed.
Prevention
Managing a cat's litterbox -- especially in multi-cat households -- is considered the ideal approach to prevention.
References
Buffington CA, Westropp JL, Chew DJ, Bolus RR. Clinical evaluation of multimodal environmental modification (MEMO) in the management of cats with idiopathic cystitis.
Buffington CA, Chew DJ, Kendall MS, Scrivani PV, Thompson SB, Blaisdell JL, Woodworth BE. Clinical evaluation of cats with nonobstructive urinary tract diseases. Journal of the American Veterinary Medical Association [1997, 210(1):46-50]
Cooper LL. Feline inappropriate elimination. Vet Clin North Am Small Anim Pract. 1997 May;27(3):569-600.
Horwitz DF. Behavioral and environmental factors associated with elimination behavior problems in cats: a retrospective study. Applied Animal Behaviour Science1997. March; 52(1): 129-137.