Yes—Doordog can connect to most doors.
Metal doors/fridges: It attaches directly using the built-in magnet.
Non-metal doors (wood, fiberglass, etc.): Use the included metal plate + adhesive strip so the magnet has something to grab.

As long as the surface is clean, flat, and dry where you place the plate, you’re good to go.

Not much—Doordog works for most dog sizes, because the goal is teaching the behavior (pushing) more than relying on strength.

That said, size can affect which doors are realistic:

Small dogs: do great on lighter interior doors once trained, but heavy/stiff doors may be harder.

Medium/large dogs: can handle a wider range of doors, including heavier ones.

If your dog can comfortably reach the Doordog at the height you place it, they can learn it.

No—Doordog shouldn’t damage your doors.

For non-metal doors, it uses included non-damage adhesive strips (Command™-style) and a metal plate, so the magnet attaches to the plate—not your door.

Not recommended on peeling paint, fresh paint, or delicate finishes.

Doordog works best with food motivation, since the design uses treats to teach the pushing concept.

If your dog has any food drive, it can work—you may just need more patience. Dogs that are highly food-motivated usually learn faster than dogs with lower food drive. The good news: food drive can be built with the right approach.

Most dogs will be closing doors on day one when you use food inside the Doordog.

To master the command without needing food or the device, it typically takes 1–2 weeks of consistent practice. The transition piece makes that step-by-step progression smooth and seamless.