Mechanical forces imposed on lung tissue constitute major stimuli for normal lung development and post-pneumonectomy (PNX) compensatory growth and remodeling. Superimposing developmental signals upon PNX signals augments compensatory alveolar growth but exaggerates airway-parenchymal dissociation (i.e., dysanaptic lung growth); the latter tends to offset benefits derived from the former. In adult dogs after PNX, lobar expansion and growth of the remaining lobes were markedly non-uniform (Ravikumar et al. J. Appl. Physiol. 97:1567-74, 2004). We hypothesized that superimposing developmental and post-PNX signals further accentuates non-uniform lobar growth. We utilized high resolution computed tomography (HRCT) to follow regional lung expansion and growth in foxhounds undergoing right PNX at 2.5 mo of age compared to litter-matched control (SHAM) animals; scans were performed 4 and 10 mo following surgery, i.e., before and after somatic maturity. Air and tissue volumes were measured in each lobe; tissue volume estimated by HRCT includes air-free tissue and blood in small vessels <1mm. Inter-lobar non-uniformity of tissue volume was absent at 4mo but evident 10mo after PNX; growth of the remaining left lower lobe gradually lagged behind other lobes. At maturity, non-uniformity of lobar growth in pneumonectomized puppies was similar to that previously reported in pneumonectomized adults. We conclude that superimposing developmental and post-PNX signals enhance some aspects of compensatory lung growth and remodeling without altering its non-uniform spatial distribution.