Cat litter generally needs to be changed about once a week, but this depends on the type and quality of the litter. Clumping litter needs to be changed more frequently, while absorbent litter can last longer. High-quality crystal litter, for example, generally needs to be changed once a month. However, product quality varies, and some inferior litter may not be effective. Owners should regularly observe changes in the litter; if they notice an odor or increased dust, it should be replaced immediately. 
Consequences of not changing cat litter:
1. It will breed bacteria. If cat excrement is not cleaned in the litter box for a long time, a large number of bacteria will grow, and parasites may also appear, which is very unhygienic.
2. It can cause illness in cats. Cats that defecate in unsanitary litter boxes are more susceptible to bacterial and parasitic infections, leading to urinary tract diseases and other ailments.
3. It can cause cats to urinate indiscriminately. Cats are very clean animals; they can be quite fastidious and dislike defecating in a dirty litter box, so they will look for other suitable places to relieve themselves.
