I claim the ornamental design for a pet collar with a detachable portion, as shown and described.
FIG. 1 is a perspective view of a dog collar with a detachable portion showing my new design, in condition of use;
FIG. 2 is a perspective view thereof, shown in an alternate configuration;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a is a right side elevational view thereof;
FIG. 6 is a left side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken line showing of a pet and collar pendant in FIG. 1 depict environmental matter and form no part of the claimed design. The broken lines in FIGS. 2 through 8 represent stitching, and are part of the claimed design.