You will learn what in the tray itself can explain deposits beside it, before drawing any conclusion about the animal.
Some links on this page earn us a commission if you buy after clicking. It changes neither the ranking nor what is written here — and we say below what we were unable to check.
When a cat stops using its tray, we look for a reason inside the cat first. Some of those reasons are made of plastic, and can be measured with a tape.
A cat does not simply sit down. It steps in, turns, digs first, positions itself, digs again, and covers. That sequence needs an area, not a spot.
The rule usually given can be checked with a tape: the tray runs about one and a half times the length of the cat, nose to base of tail. Plenty of shop trays fall short, including ones sold for large cats.
The cheapest way out of this is not in the pet aisle: a plastic storage box, wide and low, does the same job for a fraction of the price.
Stepping over a high edge means carrying the whole weight on the hind legs for the length of the step. A cat with sore joints does it less and less willingly, and it does not warn you.
The sign is readable: it goes against the outside wall, or just in front of it, never far away. It is aiming at the right place and no longer reaching it.
A low cut-out on one side is enough. You can buy one, or cut one into a storage box and file the edge smooth.
The lid solves your smell problem in the room. At the same time it concentrates ammonia in a closed volume, exactly where a nose far finer than yours happens to be.
It also removes the exits. An animal that cannot see what is coming up behind it while it crouches may simply decide to go elsewhere.
The check costs nothing: take the lid off for a week and watch what changes. If everything settles, you have your answer.
A cat digs hard. The liner tears, urine runs underneath and sits between plastic and film, and the tray smells even though you have just changed it.
Liners exist to save you a rinse. It is the easiest spend in this whole piece to cut.
The end of a corridor with no second way out, a cupboard beside a washing machine that starts by itself, a corner pressed against the food bowl: each of those three choices hands the cat a reason to go elsewhere.
What you are after is easy to describe: quiet, two ways out, well away from food, and reachable without walking past the other animal in the house.
The rule that circulates among feline vets is one tray per cat, plus one. It is not about available volume, it is about never being blocked.
It only counts when they are spread out. Two trays side by side count as one: a cat guarding the doorway is guarding both.
A scented block or a scented litter adds a smell the animal did not choose, inches from its nose, in the one place where it has no choice.
A motorised tray adds noise and movement in that same place. Some cats put up with it, others simply stop using it, and the failure gets paid for in rugs.
What works stays dull and free: scoop more often.