FIG. 1 is a perspective view of a first embodiment of a cat door;
FIG. 2 is a front elevation view of FIG. 1;
FIG. 3 is a bottom plan view of FIG. 1;
FIG. 4 is a rear elevation view of FIG. 1;
FIG. 5 is a right elevation view of FIG. 1;
FIG. 6 is a top plan view of FIG. 1;
FIG. 7 is a left elevation view of FIG. 1;
FIG. 8 is a perspective view of a second embodiment of the cat door;
FIG. 9 is a right elevation view of FIG. 8;
FIG. 10 is a front plan view of FIG. 8;
FIG. 11 is a left elevation view of FIG. 8;
FIG. 12 is a bottom plan view of FIG. 8;
FIG. 13 is a rear elevation view of FIG. 8; and,
FIG. 14 is a top plan view of FIG. 8.
The broken lines showing the cat depicts environmental subject matter that forms no part of the claimed design, while the remaining broken lines shown in the drawings depict portions of the cat door that form no part of the claimed design.