Upper panel: percentage of resistant staphylococcal isolates from control and treated dogs. Middle panel: respective results of E.coli. Lower panel: resistance in staphylococcal isolates from younger and older dogs regardless of treatment history. Significant differences marked by an asterisk. Abbreviations: β-lact+ = betalactamase positive, amp = ampicillin, clin = clindamycin, ery = erythromycin, strep = streptomycin, sxt = sulphatrimethoprim, tet = tetracyclin, >1 = resistant to one or more antimicrobials, multires = multiresistant isolates (resistant to three or more different class of antimicrobials).