Not wanting to jump down your throat. . .
However that's incredibly dangerous.
if he takes off all of a sudden at a tangent
either away from you or around the front or back wheels
you could be yanked and the bike would twist underneath you.
the resulting crash could injure you very badly possibly also the pooch,
or he could get away from you in the process and be off.
Please, please, please, if you want to ride with the dog get a Walkydog / Springer atacchment
or bikejoring attachment and harness.
they make it Safe.