Hi Jp,
I was just looking in my trusty Feline Medical book and it looks like Opus could be right. Has your cat ever had heart problems?
When there is sudden paralysis in the rear legs, conditions to consider ar:
arterial thromboembolism and ruptured disc.
Diagnosis is difficult and requires special techniques usually available at veterinary medical centers.
Symptoms: Cold legs, bluish skin, faint or absent pulses in the groin area.
This needs to be checked out, surgery may be needed if indeed this is an embolism, Either way not good to have your baby unable to walk or defecate---Back to the vets ASAP
Good luck and keep us posted,
CML
I'm so sorry for what your dear kitty is experiencing.....I am not a Vet and nothing can take the place of a good exam, but as someone who suffers from disc disease I must say this usually isn't progressive into other parts of the body or whole body and I am skeptical abt a tumor as well..
was she in alot of pain before the pain meds? I'm wondering what the Vets thought of a blood clot?...they can travel as well from the limbs
heres some reading....I sure wish her all the best of luck, please update us...
http://www.petmanage.com/cat-health/thrombosis-in-cats.html