Electric fences work by having the dog or cat wear a special collar that interacts with special underground wiring. When the dog or cat gets too close to the wiring, it gets a shock. There is nothing to stop loose animals or people, however, from getting in your yard because they will not receive a shock. This means that other dogs and cats can fight with your pet or that someone can steal your pet.

On the Other: They Can Be Safe

An electric fence is better than using nothing to contain your pet. If you are prohibited from putting up a physical fence, many dogs and cats can be trained to stay in the yard with an electric fence. This prevents them from roaming the neighborhood and possibly being hit by a car.

Bottom Line

Dogs and cats can build a tolerance to the shock and go out even though the device is working. When cats are excited by the possibility of a hunt, they will run through. Even dogs and cats that have reliably used the fence for years can decide to escape at some point, according to PetPeoplesPlace.com. There is no way to know how an animal will react to an electric fence. Therefore, the safest way to confine your dog is with a physical fence and your cat by keeping it indoors or in a large covered enclosure.

Source:

Pet Peoples Place: How Safe is Invisible Fencing? What the Average Dog Owner May Not Know

Cat Channel: Electric Fences and Cat Safety