Cat Litter Tray With Lid

PupProtein

I’ve been researching various types of cat litter trays, and I’m curious about the implications of using trays with lids. There’s a lot of debate around whether a lid is beneficial or harmful to a cat’s wellbeing. On one hand, it can provide privacy and minimize the mess and odor in the house. On the other, some argue that it might trap smells inside, making it uncomfortable for the cat, or it might be seen as a restrictive space, especially in multi-cat households where it could lead to territorial issues.

Additionally, could the use of a covered litter box influence a cat’s litter box habits in any significant way, perhaps even causing stress or behavioral problems? How do these factors weigh against the practical benefits of using a lid? Is there any concrete research or expert opinion that could shed light on the effects of using covered versus uncovered litter boxes for cats’ health and happiness?

Looking forward to hearing your experiences and any evidence you might know of!

FluffyFuel

What changed my mind on lids was two things: size and social dynamics. Most covered boxes are simply too small, and they create a dead-end in multi-cat homes.

Evidence: A small crossover study (Grigg et al., J Feline Med Surg 2013) found no overall population preference for covered vs. uncovered-individual cats varied. Cleanliness and box size mattered more than the lid itself.
Guidelines: AAFP/ISFM house-soiling guidance leans toward large, open boxes-especially in multi-cat settings-so cats can see threats and have multiple escape routes. If you insist on a cover, skip the flap and make sure the opening is generous and the box is bigger than average.
Size is the sleeper variable: Aim for at least 1.5× the cat’s body length (nose to base of tail) in both length and width. Most commercial covered boxes don’t meet this, so cats end up cramped and turning in urine-soaked corners.
Odor: A lid hides smell from humans but concentrates it for the cat. Scooping 1-2× daily and weekly washing does more than any cover or charcoal filter.
Social stress: In multi-cat homes, lids increase ambush risk. I’ve seen guarding drop just by switching to big, high-sided open boxes placed so there are clear sightlines and multiple exit paths.
Special cases: Seniors, large cats, and arthritic cats often do better without lids (less crouching/twisting; better ventilation). Dust-sensitive cats too.

Practical compromise: use an extra-large, high-sided uncovered tote (under-bed bins are great) to control scatter without turning it into a tunnel. If you’re unsure what your cat wants, run a two-week A/B test: two identical boxes, identical unscented clumping litter, one with a lid (no flap), one without, and count deposits. Your cat will cast the deciding vote.