Is it safe to assume that the change in a dislocations' burger's vector size is negligible during loading?

As a result of loading, there is grain distortion, which results in lattice distortion. when lattice distortion happens, then lattice parameter changes. The change in lattice parameter, (a), results in a dislocation's burger's vector size change, since it has the lattice parameter size in its formula. Consequently, one can conclude that the size of burger's vector of a dislocation changes as a result of loading! . Still, is it practically safe to assume that the the change in its size is negligible compared to its initial size before loading?