Install A Pet Door
Determine the size of door you need before you buy, by measuring the shoulder width of your pet.
Measure the tummy height of the animal from the ground and use this to determine the distance from the floor to the base of the pet door.
The base should be no higher than tummy height so that the animal can pass through easily.
Also consider the agility of your pet. An old arthritic dog or overweight cat won’t use the entry if it requires an energetic climb or leap of faith.