trouble walking and standing

Sofia is 10 years old. Two months ago I noticed that she had trouble walking. She would raise her lower body and was barely able to move her hind legs (video). However this didn't last long. Last month the something happened, but again she was OK in a few days. The vet didn't think there was anything wring with her and he didn't think it was related to Ca/P deficiency. However right now the condition progressed. The entire last week she was not able to walk normal. I can tell that she is in pain, because sometimes she makes sounds, and sometimes she bites her cage-mate for no reason (and me). Do you guys have experience with this? The VET thought she simply sprang her ancle, which is obviously not the case. It's all four legs now (video).

https://youtu.be/d7bxyfjfYsM
https://youtu.be/_k-je3bBYiY

There is definitely something wrong with your sweet Sofia. I'm surprised the vet couldn't see her overall condition isn't healthy or that she has difficulty with mobility. Did he by chance see your videos? Sometimes seeing them at the vet's office and seeing them in their natural environment will make all the difference.

I wouldn't rule out anything at this point. What diet are you feeding?

Thank you for your reply. I was feeding them pellets + veggies and fruits (She gets constipated from HPW). Now I give her HPW every other day in case she has a protein deficiency.

When you feed f/v, are you paying attention to the calcium to phosphate (2:1) ratio? Too much phosphate will keep the body from absorbing the much needed calcium. Ironically the body does require some phosphate to help absorb the calcium. That would be the 2 calcium to 1 phosphate ratio 2:1.

The HPW should be fed every day rather than every other day. There are ways to help with constipation, however, a balanced as well as consistent diet usually takes care of that.