If the diagnosis is correct, the IM assuming the 'bleeding in the spine' means a fibrocartilagenous embolism - a tiny clot in the spinal cord.
This condition is sudden onset, typically not painful for the dog.
There is no veterinary treatment for this - only rehabilitation will help your pet improve.
But it does require typically a CT scan for an accurate diagnosis to make sure there is no disc prolapse. This has to be perform med by a veterinary surgical specialist
How quickly the dogs recover depends on severity of signs at the outset.
Typically if your pet is walking already by 3 weeks post incident then return to function should be almost if not 100%, but should certainly have some physio exercises to perform at home.
How is he currently?