Why Extension Tethers Are Not Safe

Center for Pet Safety restricts brands that sell extension tethers from participating in the CPS Certified® program. Our research shows these devices violate basic passenger-safety principles and can negate any crash-protection claims made by the harness manufacturer.

What We’ve Learned From Real-World Incidents

Pet owners have reported devastating injuries when their dog was connected to an extension tether during a crash. These injuries are not minor. They are painful, expensive, and emotionally traumatic. Some families have spent tens of thousands of dollars trying to save their pet after an improper restraint failed.

How Extension Tethers Cause Injury

Extension tethers give pets too much movement during a sudden stop or crash. When the vehicle suddenly decelerates, the dog is thrown forward and then snapped back, creating a “clothes-line” effect that places extreme force on the spine.

Because the dog is able to shift and brace to stay on the seat, this excess motion also increases the risk of orthopedic injuries, including ACL tears, hip trauma, and spinal damage. CPS has received multiple reports of these types of injuries.

Common injuries linked to extension tethers include:

• Paralysis
• Blunt force trauma
• Catastrophic spinal damage that can lead to organ failure, resulting in humane euthanasia

Don’t Be Misled by Online Marketing

We regularly see extension tethers promoted on Amazon, Facebook, and other social platforms as “safety devices.” Most of these products are untested. Manufacturers often rely on marketing — not science — to convince you to spend your hard-earned money.

Even Trusted Brands Sell Unsafe Add-Ons

Some well-known pet product brands offer extension tethers or zipline-style accessories. Even if their harness has undergone some testing, these add-ons cancel out any crash-protection benefit.

How to Travel Safely With Your Pet

• Use a CPS Certified® harness, crate, or carrier
• Never attach an extension tether or zipline device
• Secure pets in the back seat

See the CPS Certified Products directory or contact us.