older cat yowling -- both at night and during day
I have an older female cat, who turns 18 years old here in January 2010. She is a calico tortoise shell, orange and black and white, and very personable and talkative in general. Not too "skittish" like some cats typically are, but very friendly and outgoing. We live in Minnesota, where its ridiculously cold right now, and she is an indoor apartment cat.
A few years back, maybe about 3-4 years ago, she started to develop a problem with picking out clumps of fur, and I took her to the vet for it, they ran some blood tests to check her thyroid and some skin tests, and everything came back okay. The problem with "fur picking" seems to have faded away and is not really an issue anymore.
My current question (or problem) stems from her yowling. Not just at night, but virtually anytime during the day, when anyone (myself particularly) is around to listen or pay attention. Sometimes it seems to just be a clever ploy for attention, because she'll start yowling (sounds like she is "screaming bloody murder"), but then as soon as anyone takes notice and says "what's wrong?" to her in a soothing voice (or something like that), she quiets down and everything appears normal. Due to her old age and arthritis (I think?) she is unable to leap or jump like younger cats do. She cannot make it onto the bed or couch, so sometimes she'll yowl -- not just meow, but yowl like "screaming bloody murder" -- while sitting next to the bed. Then I'll go in there, ask her what's wrong in a soothing voice, and everything seems fine. I'll lift her up onto the bed, and usually she takes a nap and everything is fine, stops yowling.
She does not appear to be in pain or favoring any particular part of her body that might be bothering her. She has some very occasional diarrhea in the litter box, but nothing that seems too frequent or too abnormal. Her appetite does not seem to be a problem -- she eats regularly (used to be just dry food, but now we feed her canned wet food also, she's lived this long, so I want her to enjoy her golden years).
I guess that my confusion is I'm not quite sure what she is yowling about so much (at night and during the day), aside from wanting to be placed up onto the bed, and she does not appear to be in pain or having any real major problems, so I'm hesitant to go into the vet and spend $200+ (money that I do not have) for them to say "nothing wrong with her, she's just an older cat who likes to yowl".
Are there any other things or remedies or whatever that I should be doing with her to make sure everything is okay? I want to make sure she is okay, but I want to avoid a hefty vet bill at the same time.
Thank you very much for any input or suggestions.