Experts often put trolley dog runs forth as a way for people without adequate fencing to ensure their dogs get proper outdoor exercise. While some advocates tout trolley dog runs as being better or more humane than simple chaining and tethering, they can, in fact, be just as dangerous and detrimental to the health and well-being of your dog as chaining and tethering.
Tangling and Choking
Dogs hooked to a trolley dog run, especially if their collar is a "choke chain" or martingale collar, can be strangled to death when their collars are pulled and held tight by the stops on a trolley dog run.
The trolley wire can tangle the dogs, cutting off blood circulation to their limbs or the ability to breathe.
If the trolley run uses a nylon or leather cable to leash the dog to the trolley, the dog can chew through the cable or choke on bits and pieces of the hardware.
Limited Access to Food
Dogs that get tangled in the trolley system or wrap the lead around a tree can be deprived of access to their food and water bowls. This can also happen if the dog accidentally pushes the bowls out of the reach allowed by the tether.
Dogs clipped to a trolley dog run cannot flee animal predators, whether these are dangerous neighborhood dogs that get into your yard or local wildlife such as hawks, cougars or snakes. This leaves them susceptible to injury or death at the hands of these animals.
They also cannot flee human predators such as those who steal purebred dogs for breeding or scientific purposes or unstable people who may harass animals.
Boredom and Destructiveness
Dogs that require a great deal of energy and exercise often become bored when attached to a trolley, which does not provide them much room for exercise or exploration. This can often lead to destructive behaviors, such as digging and barking, or nervous tics such as chewing their fur off in a particular area.
Dogs left without occupation or adequate human interaction for considerable lengths of time can also become aggressive, leading to an increased potential for dog bites and food aggression.