That is how you stop any attacking dog.
It is not, however, what I would do in this situation.
Something has clearly changed in the dog.
That needs to be discovered and addressed.
I would bet money on thyroid.
ALL Dobes are prone to hypothyroidism.
Blues and fawns, doubly so.
MY mutty has Thryoid issues but it slows him down.
It dont speed him up.
But he aint a Dobe, he is a Black Lab.
Different breeds are different.
But Dogs are pretty easy to understand IMHO.
They are pack animals.
You are in charge or they are.
For the record, Dobes are some of the finest loyal lick yer kids and protect the house dogs ever.