Guide · · 4 min read
One pet door for a cat and a dog: how to choose
A cat will happily use a door sized for a small or medium dog, so one door often does both. Size it for the dog, set the height for both, and know when two doors are better.
By the Pet-Tek International team, Auckland — designers of Catwalk® and Dogwalk® since 1999.
Plenty of New Zealand homes have both a cat and a dog, and nobody wants two holes in the back door if one will do. The good news is that one pet door often works for both, as long as you size it for the right animal and get the height right.
Size it for the dog
The door has to fit the bigger animal. A cat will happily use a door sized for a small or medium dog; a dog cannot use a door sized for a cat. So measure the dog first: shoulder height for the door size, and the widest point of the chest or hips (plus 25 mm) for the opening width. Our measuring guide takes five minutes.
- Small dog (to about 300 mm at the shoulder) and a cat: the Catwalk® Maxi. It was designed for large cats and small dogs together, with a 187 × 190 mm opening. It fits glass, including double glazing (3–28 mm), or a slider as the Maxi Slim Line.
- Dog to about 380 mm: the Dogwalk® Intermediate (216 × 237 mm opening) in glass; for dogs to about 360 mm, the Dogwalk® Small in a wooden door.
- Dog to about 500 mm: the Dogwalk® Medium in glass, or the wood-fitting Medium. Cats use it too.
Get the height right for both
Size the door for the bigger animal, then set the bottom of the opening at the smaller animal’s belly height. The smaller pet steps straight through instead of climbing, and the bigger one steps over a low sill, which is easy for it. With a cat and a small dog sharing a Maxi, their belly heights are usually close anyway. Allow for the bottom rail of the door frame, and give both pets a flat landing outside.
Teaching both to use it
Dogs usually get it in a day; cats can take a week. Start with the flap propped fully open so the door is just a hole, call each pet through with food, then lower the flap and help them push. Teach them separately so the dog’s enthusiasm does not put the cat off. The training guide has the full method.
When two doors are better
One shared door is simplest, but two doors make sense when:
- The dog must stay in but the cat should come and go, for example at night or when you are out.
- The dog is big and you do not want an opening that size open all day.
- The cat food must stay cat-only.
The usual set-up is a dog door you can lock with its 4-way dial, plus a cat door that only opens for the cat: the Catwalk® Multi-Magnetic for glass or the wood-fitting Multi-Magnetic, which open only for a cat wearing the collar magnet. The dog cannot open it. Two doors can go in different panes, or a glazier can fit both in one large pane with enough glass between them.
The microchip option
If you would rather have one door that knows who is who, the SureFlap Microchip Pet Door Connect reads the microchips your pets already have and lets in only the animals you register, so stray cats stay out. Its 178 × 170 mm flap suits large cats and small dogs, going out is always free, and with the SureFlap Hub (sold separately) you can lock it from your phone and see who came and went. For glass, add the mounting adaptor. More on the SureFlap page and in our microchip vs magnetic guide.
Security with a bigger opening
A door big enough for a dog is a bigger hole, so lock it at night and when you are away. On glass-fitting Dogwalk® doors, a security clip holds the dial in the locked position. Our pet door security guide covers placement and habits.
Still deciding? Read how to choose a dog door and how to choose a cat door, find your door, or email photos of both pets and the door to info@petnest.co.nz.
Quick answers
Can a cat and a dog use the same pet door?
Usually, yes. Size the door for the dog, because a cat will happily use a door sized for a small or medium dog. The Catwalk Maxi was designed for large cats and small dogs together; bigger dogs need a Dogwalk door, which cats use too.
Will a cat push a dog door flap?
Most cats do, after a short introduction. Prop the flap open for the first few days so the door is just a hole, then lower it and help your cat push it. Cats learn quickly once food is on the other side.
How do I let the cat out but keep the dog in?
Fit two doors: a door that only opens for the cat, like the Catwalk Multi-Magnetic (collar magnet), and a separate dog door you can lock. Or choose the SureFlap Pet Door Connect, which lets in only the pets you register with it.
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