The ornamental design for a dogbed, as shown and described.
FIG. 1 is a top, left and rear perspective view showing my new design;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a left-side view thereof;
FIG. 6 is a rear view thereof; and,
FIG. 7 is a right-side view thereof.
The broken lines found in FIG. 1 and FIG. 2 represent stiches located along the center of the dog bed. Also, the small curved lines found along the interior perimeter of the topper portion of the dog bed represent gathering of fabric.