Bless her, but 12 is great!
Do you know which tube bulb brand you have been using in the past, up until now? Unfortunately,
not all of them are good.
Which brand are you planning on getting, the stores might not have a good brand available. We
recommend the Reptisun 10 or the Arcadia D3 12%. Since you already have a regular T8 tube bulb
fixture, you can continue with a T8. If you at some point, wanted to change things out to a high output
T5 tube bulb, you can do that also.
What type of calcium are you giving, a powder or liquid?
Neurological issues are usually caused by injury, stroke, or calcium issues. Adenovirus causes
neurological problems too, but I highly highly doubt that would be a consideration based on her age
& it just coming on this suddenly. Chances are her 25Hydroxy (D3 measurement level) could have
been dropping for awhile. Their body can hold & maintain calcium stores for quite awhile, possibly a
few years depending on genetics but they will start to fall overtime if they don't have adequate UVB
exposure. Without strong enough UVB exposure, they cannot properly absorb calcium so their blood
serum gets lower & then the body draws calcium from the bones to help maintain blood serum levels.
Once that begins to happen, it will start to manifest physical symptoms such as neurological trouble.
Let's see if better lighting will help before treating her for any type of infection yet.
Let us know how she is doing.