[Gpdd] HEALTH: Older than we think?

[Cuttlefish Arts]

We have a female GP that we believe to be somewhere between 4 and 5 years
old -- she came from a shelter, and was supposed to be "about a year old".

Over the last year, she has become thin and lost much of her ability to
walk. At first she just "bunny hopped". Now she's really very nearly unable
to get around. She has an appetite, and eats on her own, but can't seem to
gain weight. She's in good spirits, I keep her clean and give her critical
care to keep her weight up; she doesn't appear to be in any particular pain.
She isn't really able to squeak anymore, either, almost like she's lost her
voice. 

Let me just say; we've worked with a reputable exotics vet, and we have been
able to find no organic reason for her problems, other than some arthritis
and some slight spinal fractures that might have happened when she was
small; we've researched her problems very intensely and not come up with
anything. We just keep her going the best we can. Her housemate, a 4 year
old neutered male, adores her.

In the past 6 or more months, we have noticed white hair appearing on her
black areas (she's a dutch/mixed) and kind of wonder if she just isn't
really very, very, old? I know it could be stress from her illness, but I've
never actually had a cavy get extremely old, they all seem to end up passing
away at about 5 1/2 years old, despite our very good husbandry. She was
pretty large when I got her from the shelter and the more I think about it,
I wonder if it's typical that a 1 year old female would be that big (almost
3lbs when we got her.) Of course, if she had babies before that, that's
maybe not THAT big.

Anyway, anyone out there have any experience with elderly guinea pigs? Any
insight would be appreciated, especially what really old age looks like in a
GP so we can better evaluate her. We're dedicated to keeping Angela going as
long as her life is comfortable.