Knoxville (WVLT) -- A company that installs electronic monitoring fences in East Tennessee says your pet still needs training.
This is after a woman claims her dog was attacked by bull mastiff dog.
Volunteer TV's Stephen McLamb has an update.
Greta Wilson says on Thanksgiving day, she and her children were walking their dog when the bull mastiff attacked the dog.
Wilson says her dog's collar broke and her dog took off, so the attack ended.
The dog's owner claims the bull mastiff was in the yard surrounded by an electronic monitoring fence, which is basically an invisible barrier that is supposed to keep your pet inside it's yard.
PetSafe is responsible for installing Invisible Fences in East Tennessee and in more than 300 locations across the country.
They say you pet also needs training or the fence may not work properly.
A dog owner along Farrington Drive claims her dog couldn't have gotten out of her yard and attacked a neighbor's dog because they had installed electronic pet monitoring.
But a Knoxville maker of electronic pet monitoring says nothing is fool proof.
"There is no absolutes. I mean a dog can get over a traditional chain link fence," said Mark Thomas, Senior Brand Manager for Invisible Fence.
But Thomas says their product can be hugely successful if used properly.
"Has about a 99.5% chance of keeping your dog in," he said.
Electronic pet monitoring comprises of an underground wire with above-ground flags that surround your yard or safe zone, along with a dog collar that provides an electronic shock to your pet if they get close.
Part of using your equipment properly is installing and maintaining it.
"You need to make sure that the power source in the receiver and the transmitter are constant because it's got to work every time it's used," said Thomas.
But more importantly than most people realize, Thomas says using electronic pet monitoring requires training.
"It's got to be fair to the dog. He has to know where his boundaries are. He needs to know where he needs to stay and that's what the dog training does," he said.
Thomas says they provide two to three sessions of training with their product with challenges.
"We bring other dogs out for a distraction. We have the customers and the family members leave the property. We test these things before we say your dog is okay to be here," said Brian Atkison, with Invisible Fence Operations.
Without training, invisible fence officials say the dog learns the shock will end, making it less effective.
"Dogs that aren't trained don't understand the concepts of it, therefore it can run through because it does have an ending point," said Atkison.
If your pet does get out of your yard, you can be cited.
Tim Adam with Young-Williams Animal Shelter says a "dog at large" citation can cost you $50 plus court costs.