Measure your pet for the correct size pet door

There are two measurements to consider:  (1.) Height of the top of the opening; (2.) height of the bottom of the opening. If the Height is correct, the width will be automatically correct. 

(1.) HEIGHT:  How high should the top of the opening be? Measure your pet at the shoulder. The top of the opening should be 1" to 2 inches above the shoulder of the largest pet.

(2.)  Height of the bottom of the opening.  How high should the bottom of the opening be? The bottom should be low enough so your pet can walk through without a problem.

If you have multiple pets, make sure the bottom of the opening is low enough for the smallest pet to go through without a problem.  The door that is big enough for a collie may be too big for a westie, or even a large cat and you may wish to consider two doors.

Make sure the pet door you get has a large enough opening to cover both the top and bottom requirements of your pets.