Why is my cat peeing outside the litter box?

Why the vet visit comes first

FLUTD (feline lower urinary tract disease), bladder stones, urinary tract infections, kidney disease, and diabetes all commonly present as inappropriate urination. Treating the behavior with litter changes when the underlying cause is medical means the cat suffers longer and the problem doesn't resolve. A urinalysis and urine culture cost less than a month of frustration.

Litter-box setup that actually works

• Number: one box per cat plus one extra. Two cats → three boxes.
• Size: 1.5× the cat's body length. Most commercial boxes are too small.
• Location: spread across the home, not lined up in one closet. Multiple rooms, multiple floors if applicable.
• Type: most cats prefer uncovered, low-sided boxes; covered boxes trap odor (for them, not just for you).
• Litter: unscented, clumping, fine-grain clay or equivalent. Most cats reject scented or pellet litters.
• Cleanliness: scoop daily, full empty-and-wash every 1–2 weeks. Cats avoid soiled boxes.

Social stress between cats

In multi-cat households, inappropriate urination often signals resource competition or one cat blocking another from a box. Vertical territory (cat trees, perches), more boxes in more locations, and Feliway diffusers can help. If a specific cat is bullying others, a behavior consult is warranted.