What should I do if I notice a sudden change in my cat’s behavior?

What should I do if I notice a sudden change in my cat’s behavior? - Countryside Veterinary Clinic

I would make an appointment with the vet or at least call them because there are a lot of things that cats can do that might not seem like a problem, and that might not seem serious at home that can be an indication of an extremely serious issue, so it's best to talk to the vet right away.

What should I do if I notice a sudden change in my cat’s behavior? - Advanced Animal Care of Mt. Pleasant

A sudden change, any change, whether behavior or some physical attribute, are the things that are really important to us as doctors in knowing when there's a problem and how we should approach it. So the first moment you notice a change in their behavior, that would be the time really to start asking the question and maybe seek out your veterinarian to help you with that.