Cornell's feline health center calls house soiling "the most common behavior problem reported by cat owners," and the feline practitioners' guideline on it says the thing owners most need to hear: "this unwanted behavior is not due to spite or anger towards the owner, but because the cat's physical, social or medical needs are not being met." The first of those is medical, which is why the first stop is the vet, not the pet store.
The 2014 AAFP and ISFM guideline tells vets to "perform a thorough physical examination (including a basic orthopedic and neurologic assessment) on every house-soiling cat," and lists the medical causes to exclude: "urolithiasis, chronic kidney disease, urinary tract infections, diabetes mellitus, hyperthyroidism, arthritis, orthopedic etiologies and neoplasia." Two of those deserve a word.
They are different problems. Toileting is ordinary urination or defecation in the wrong place, usually a puddle on something horizontal and soft: a rug, a bed, laundry. Marking is spraying: "a spraying cat will stand, lift its tail and quiver, then spray small puddles of urine in several consistent locations," usually on walls, chair backs and doors (Cornell). Neutering ends most of it, but the guideline notes "approximately 10% of neutered male cats" and about 4% of neutered females keep marking. Marking is about other cats, real or through the window, and a change in the house.
These are the recommendations in the feline practitioners' guideline, Cornell's page and Ohio State's Indoor Pet Initiative, and they agree with each other.
| Recommendation | Who says | |
|---|---|---|
| How many | One more than the number of cats. Two cats, three boxes. | AAFP/ISFM, Cornell, Ohio State |
| How big | 1.5 times the cat's length, nose to base of tail. Most boxes sold are too small. | AAFP/ISFM |
| Covered? | No. "Open boxes are recommended whenever possible." Covers trap smell and let another cat corner the user. | AAFP/ISFM, Cornell, Ohio State |
| Litter | Fine, sand-like, unscented, clumping, at least 1.25 inches deep (Ohio State says about 2). | AAFP/ISFM, Cornell, Ohio State |
| Cleaning | Scoop at least once a day. Wash the box weekly with mild dish soap. | AAFP/ISFM, Ohio State |
| Where | Quiet, private, easy to reach, on every floor, away from food and water, not next to a furnace or washing machine that switches on. | AAFP/ISFM, Cornell, Ohio State |
| Old or sore cats | Low sides. Kittens and overweight cats: low sides and a bigger box. | AAFP/ISFM, Cornell |
Change one thing at a time and give it a week. If the cat used the box for years and stopped, the box did not change; something else did. New cat, new baby, new furniture, a neighbor's cat at the window, a box moved to the basement.
The feline environmental needs guideline lists five pillars: a safe place; multiple, separated resources (food, water, boxes, scratching, play, rest); the chance to play and hunt; predictable, consistent human contact; and respect for the cat's sense of smell. The one that matters here is separation: "toileting areas should always be located away from food and water dishes," and in a multi-cat house each resource in its own place, so a cat can reach a box without crossing another cat.
Urine that is not fully removed invites a repeat. Use an enzyme cleaner made for it, not ammonia, which smells like urine to a cat. And Cornell, verbatim: "you should never hit, kick, or scream at a cat. Punishments like these are not only ineffective, the anxiety they cause may actually worsen the house soiling problem."
In the largest US study of why people give up pets, house soiling was "the most frequently listed behavioral reason for relinquishment of both dogs and cats when mixed reasons were provided," and was named for 43% of the cats surrendered for behavior alone. Most of those cats had a fixable reason. The vet visit and the box changes above are cheaper than the alternative, and a great deal cheaper than a new sofa.
Straining in the box with little or no urine is an emergency, not a litter box problem: My cat is straining and passing nothing. Is it blocked?