Besides Diabetes What Causes Dry Mouth What Could Cause My 1 Year Old Cat To Gain Weight Exponentially?

What could cause my 1 year old cat to gain weight exponentially? - besides diabetes what causes dry mouth

I wonder what could my cat for 2 years (and lead more unwanted or dry food for cats) for 2 pounds in 1 month? My cat is the weight gain of dry food, and changed his wet food before 4 months ago. She lost a pound, and it was 10 pounds. Recently Tho, which went from 10 pounds to 12 pounds in one month! She is an indoor cat not to eat elsewhere. I wonder whether there is a specific disease that could cause this, as this has never been a problem before .. ? Maybe diabetes? I go to the vet, but I wonder what this could mean before you go .. My other cat is to be healthy, and 2.5 years old.

Thank you!