Hello, my cat (9yo, female, very slightly overweight) has suddenly started drinking more water than usual (almost a cup a day). She has had no prior health issues, and has had annual checkups and vaccinations since I adopted her 7 years ago. I don't detect any other symptoms or health problems-- energy level seems normal, nothing unusual in litter box, etc.). Should I take her to the vet? Absent any visible symptoms, are there tests that can be done for diabetes, etc. that increased water drinking is sometimes a sign of? Thanks.