  We consider the finite temperature phase diagram of holographic QCD in the
Veneziano limit (Nc large, Nf large with xf=Nf/Nc fixed) and calculate one
string-loop corrections to the free energy in certain approximations. Such
corrections, especially due to the pion modes are unsuppressed in the Veneziano
limit. We find that under some extra assumptions the first order transition
following from classical gravity solutions can become second order. If stringy
asymptotics are of a special form and there are residual interactions it may
even become of third order. Operationally these computations imply modelling
the low temperature chiral symmetry breaking phase with a hadron gas containing
Nf^2 massless Goldstone bosons and an exponential spectrum of massive hadrons.
A third order transition is possible only if repulsive hadron interactions via
the excluded volume effect are included.
