Hi My Dachshunds Legs Have Been Relatively Weak After She

Hi my dachshunds legs have been relatively weak after she had a stroke a few years back. She now doesn't walk up stairs or jump on the couch, however it has slowly gotten worse to the point where when she walks on concrete or any hard surface she ends up dragging her legs behind her.
She is fine in the house but when she is out this happens. Could it be serious?