The ornamental design for a pet-grooming brush, as shown and described.
FIG. 1 is a side perspective view of a pet-grooming brush according to the invention, the broken-line boxes in FIG. 1 illustrating disclaimed indicia printed on the invention;
FIG. 2 is a side view of the brush of FIG. 1;
FIG. 3 is a large-scale perspective view of only the head of the brush of FIGS. 1 and 2, the broken-line boxes in FIGS. 2 and 3 illustrate the enlarged view of FIG. 3 and form no part of the invention;
FIG. 4 is a large-scale bottom view of the brush of FIGS. 1 and 2; and,
FIG. 5 is a top view of the brush of FIGS. 1 and 2.