Without a fence a puppy may occasionally have to take his airing on a trolley line leash or running chain in the backyard. String a stout wire taut across the yard and fasten it securely to two posts, after first attaching a swiveled ring so that it will easily slide along the length of wire. One end of the dog’s leash or chain is then latched into the ring, the other end to the dog’s collar. A swivel at both ends of the leash or chain will allow turning as the dog runs up and down. It is essential that the taut wire be higher than the dog, to lift the weight of the leash or chain off his shoulders.
The trolley line exerciser has only limited use but, intelligently employed, serves as a short term aid. The danger is that the leash or chain may tangle, hobbling the dog and, in extreme cases, even choking him. The space all along the wire must be kept free of objects on which the leash might catch.
The dog on the trolley line cannot stray. But he is at the mercy of other dogs or children who are free to enter his yard and plague him. He cannot fight back or protect himself, so he should not be chained unless someone can keep an eye on him. He should also be walked and receive other exercise, since the small space in which he is free to run, always up and down, never across and around, can make him restless and resentful of such a restriction.