Harnesses are essential for any pet that will tolerate wearing one, though they are used primarily with dogs. According to the HSUS, it's the only other alternative (other than a carrier) to safely transport an animal in a car. Harnesses come in a wide range of sizes and can be adjusted to fit the chest and shoulders snugly of your pet, regardless of how large or small he is. Snoozer's Pet Safety Harness (shown here), which connects to the seat belt buckle in any car, is the only harness currently available that has been crash-tested. Using a harness allows your pet to be restrained safely without the possibility of choking by being restrained at the collar. Some harnesses utilize your car's seat belt and require your pet to be comfortable sitting on the car's seat. Other harnesses use the chest ring portion to connect to short leash, while the other end is hooked to a tie-down point in the cargo space of a wagon, minivan, SUV or pickup.