How do I know if a sudden change in my cat’s behavior is a problem? - Countryside Veterinary Clinic

Sometimes it's difficult to know if it is a problem. That's why I recommend checking with the veterinarian because, again, you could see a cat straining to urinate that you might not think is a problem that could mean that the cat is blocked, which is a serious medical issue. Again, these issues can be caused by stress, so I would say any time a cat has a change in normal behavior lasting for more than 12 to 24 hours, it's imperative to contact your vet.