Specific leashes are terrible, and dogs can shake out of them. This has happened to me on more than one occasion. It is essential to keep the dog contained when in public.
I recommend double leashing the dog, but please use one of these leashes for those who do not.
The leash itself, what it is constructed of, is not that important. The tensile strength of various materials is much higher than any dog can pull and break. The clasp is the most crucial part of the leash, it is the part that fails.
The three clasps on the right have been known to release if a dog shakes hard. What happens is the dog shakes at a frequency that allows the clasp to open for a moment. At times, when the clasp opens it slips off the collar and the dog is … LONG GONE.
The video below shows how delicate these clasps are. They have nothing to lock them in the place.
The clasps on the left lock in place, and the dog cannot shake them loose. I highly recommend that you invest in one of the leashes on the left.
The link below will take you to a page where you can purchase one of these products that will help you safely walk your dog.