WHY DID MY CAT STOPPED USING LITTER BOX?
When a cat decides to no longer use litter box, and instead finds an inappropriate place (in human terms) to use as a toilet — owners decide that the cat does it on purpose, most likely with intent of taking a revenge.
This is partly true, but not always the case. There are numbers of reasons why cat would suddenly stop using the litter tray. This problem must be taken seriously, it calls for a careful observation, and a well considered conclusion, whether the cat does this for revenge, or there other external reasons for such behavior.
Possible reasons why the cat stopped using the litter tray:
Injuries, stones in the genitourinary tract or infection (cystitis).
The cat might not have time to reach the tray due to excessive urination, or, on the contrary, is afraid to approach the tray because of painful urination. The cat might cower after urinating in the wrong place, understanding what he\she did wrong, but simply couldn’t do anything about it.
IMPORTANT: Never punish your cat, until you find the reason why he\she stopped using the tray. Carefully observe your cat’s behavior before reaching conclusions.
Litter tray.
Closely inspect the tray: maybe it is cracked, or not clean enough. Try to remember any recent changes, maybe you replaced the filler for the tray with a new one of a different kind (or even brand), or used different cleaning method or products. Maybe the tray has been moved to another place.
From personal experience: we used to rinse the tray with chlorine solution. But at some point I used a different bleach, and the cat, after sniffing the tray for a while, turned around, ran out of the toilet, and used a rug in a hallway as a tray. Personally I think all bleach smells the same, but the cat simply refused to use the litter tray, if it was not treated with proper chlorine solution.
Jealousy.
If a new member of a family, or a new animal, appears in your house, the cat will most likely attempt to attract your attention. Cats are very jealous creatures, keep that in mind. What should you do in such situation? Caress your cat, slightly more than usual, let him know that nothing terrible has happened, and that he\she is also loved and appreciated.
Also, don’t forget that cats can be vindictive. Not all cats are, but there are unique individuals that can take revenge on their owners. Be attentive to your pet, do not hurt or otherwise offend them, and they will be grateful to you.