A Hamiltonian formulation of the guiding center drift orbits is extended to pressure anisotropy and field perturbations in axisymmetric systems. The Boozer magnetic coordinates are shown to retain canonical properties in anisotropic pressure plasmas with finite electrostatic perturbations and electromagnetic perturbed fields that solely affect the parallel component of the magnetic vector potential. The equations of motion developed in the Boozer coordinate frame are satisfied by direct verification of the drift velocities. A numerical application illustrates the significance of retaining all second order terms.