John Doe wrote:
Circuit breakers have been used for ages (here in the United
States). They are used on every circuit in a house. Problem is,
in order to detect a short circuit, current must be extremely high
(at least over the outlet's rated current).

If you think it's not going to hurt your cats, test your theory by
cutting through a wire that's plugged into the wall. Be sure to
make a video. In case it kills you, leave a note for somebody else
to upload the video. What you will probably experience is a "BOOM"
followed by the circuit breaker tripping. And you will notice a
piece of your diagonal cutting pliers is missing.

It would be like setting off a firecracker in your cat's mouth.

You either didn't read my post, or don't understand it. I am talking about a
special kind of circuit breaker, called, "Ground Fault Interrupter" Circuit
breakers. These detect very small amounts of current leaking to ground, and
pull the breaker immediately when they do. Current drawn between one side of
the line and the other doesn't count. Its current drawn to the ground on
grounded devices that trips the breaker when it is less than 10 milliaMPS.
they use them maiunly in baths and kitchens where there is water, but there
is no reason why they can't be usede anywhere in the house, as long as there
exists a ground to draw the current. Most electrical cords arent shielded,
so the GFI wouldn;t work. But you casn get shielded cords for anything, and
as long ss the shield is grounded at the Circuit Breaker end, it will trip
the breaker as soon as 10 milliamps of ground current is detected. When a
cat chews through the shield and hits a live wire, the ground current
through the shield will trip the breaker. Ask an elecftrician about them....
He wiull be able to install them anywhere in your home that you please.