Sudden Hind leg paralysis 5 month old dog

English Mastiff with sudden back leg paralysis at 5 months old- no injury, xrays r great, MRI done, Spinal tap done- all negative. No trauma, hips look great, nothing compressing nerves. At the vet she received solumedrol x2 in IV, and then given oral steriods & antibiotics. She had seemed to recover at first then regressed now mainly only left leg affected. Same treatment again no results. Any ideas? We also tried 1 month of clindamycin. Has anyone else heard of this sort of problem? She does not appear to be in any pain, she was initially when both legs were paralyzed & she also did not have complete control of bladder. But now only left leg. I am open to any ideas. Thanks

A parasite? Tick paralysis??? Have you checked over her body for ticks?

Could be many things underlying that do not show up on x- ray mri or blood tests.

Has she been tested for Myathensia gravis ? (sp)

Could be a polyneuropathy or some sort of muscle wastage problem. I know she is very young but has she been showing any signs of intermittent lameness ? Could be a polysaccharides problem more common in horses but is possible in large breed dogs.

My Bernese had similar symptoms had many tests all negative or borderline and things that did not show up under normal testing or more thorough examinations or testing. He was 41/2 but had suffered intemittent lameness since 6 months old he also had degenerative myelopathy but was not the normal gene sod 1 but a rare mutation and it was in his neck.
The polyneuroptahy and the polysaccharides storage myopathy was the thing that affected his back end eventually. It leads to muscle tissue damage during exertion. The muscles are not able to convert the sugars needed for the muscle to grow strong.



Sorry I can't be more help and it all sounds a bit doom and gloom but having gone through similar wondered if any of these suggestions put to your vet may help.