Elder cat yowling excessively fussy eating

I have a 14 year old female indoor only cat. In January Vet determined she has start of dimentia. A lot of weight loss but no change to water/food intake other than one day she will eat one brand of food but not the next so she’s becoming picky on what she decides to eat for the day. She was yowling quite a bit for the most part only at night. Vet prescribed Xanax .75 ml once a day and once she started that the yowling stopped. For the last couple months she again started yowling and has been quite intense the last couple weeks. I can tell her hearing is not as good and possibly her sight but for the most part seems pretty healthy. However, she is not gaining any weight back and she isn’t cleaning herself as much as she is getting a lot of hair clumps around her neck on her stomach and on her tail. If I leave the lights on at night the yowling doesn’t seem as bad but still constant. I work at home so during the day there are very seldom any issues during the day. I don’t know if she is losing some of her senses so she is getting anxiety over not being able to find me. I can be standing right behind her and she won’t even know I’m there. In Jan the vet thought maybe running some labs to check liver kidneys etc but since there was no changes with food water and going to the bathroom he didn’t think it was absolute necessary. Do you all think this is just ordinary old age. Is there something OTC or herbal I could give her to soothe her at night? Anything we could be missing and should be looking for. Need some ideas before we go back to the vet.

Hello - it doesn't sound as though this patient is presenting normally - you have listed weight loss, picky eating, yowling, neglecting her coat and a lack of sensation / visual acuity. From a history alone, I might I wonder about liver, kidney, thyroid disease etc. and whether a blood sample and fresh urine sample (the latter helps to interpret the kidney levels) would be a good idea.  Even if these were to come back 'normal' (which is perfectly possible) I would continue to believe that something might not be right, and might also consider pancreatitis, arthritis and other causes of pain, lumps and bumps plus or minus, as you suggest, a problem with cognitive function.  Even negative blood tests are useful information (e.g. they might, along with a urine sample, tell you that the kidneys can cope, which might encourage your vet to try pain relief), so it is definitely worth taking your cat back to their clinician and asking what plan of action they would recommend.