I have a 16 year old girl who just suddenly started meowing loudly a lot. Mainly at night, but sometimes during the day. If she is lying with me she is fine, but when she goes into her box in the kitchen she starts yowling a lot. I took her to the vet and had her run blood work. Everything including her thyroid came back normal. The vet said it may be a mix of some eyesight loss and possible cognitive decline. She prescribed her 25mg of Gabapentin at night since she has arthritis and incase it is start of dementia causing anxiety. The Gabapentin has not helped as far as the meowing goes. Does anyone have any suggestions. Do dementia symptoms start that suddenly? She went from a quiet cat to driving us crazy in what seemed like a day. Should I have further tests done or give her something else for these symptoms?