" Thrush " It is the way 34 vesrica; doctor " or its more popular syncopation, which means people with little education, and who pronounces " dotor ". " go to the thrush " It is " go to the doctor, ".
I am not sure of the meaning of this expression. Probably refers to that in Argentina in lunfardo is said tordo doctor or lawyer, which is to say go see a doctor or lawyer.