choke collars should be avoided The Humane Society of the United States: Dog Collars http://www.humanesociety.org/animals/dogs/tips/collars.html "HSUS statement" The Humane Society of the United States: Dog Collars Dog Collars : The Humane Society of the United States http://www.humanesociety.org/animals/dogs/tips/collars.html The Humane Society of the United States: Dog Collars http://www.humanesociety.org/animals/dogs/tips/collars.html Shock collars "Dog Collars; Which type Is best for your dog?" Dog Collars : The Humane Society of the United States dog http://www.humanesociety.org/animals/dogs/tips/collars.html Humane Society: Collars "Dog Collars; Which type Is best for your dog?" Humane Society: Dog Collars http://www.humanesociety.org/animals/dogs/tips/collars.html Shock collars The Humane Society of the United States: Dog Collars Shock collars Shock collars Shock collars The Humane Society of the United States: Dog Collars The Humane Society of the United States: Dog Collars Humane Society: Dog Collars The Humane Society of the United States: Dog Collars Humane Society http://www.humanesociety.org/animals/dogs/tips/collars.html HSUS: Dog Collars http://www.humanesociety.org/animals/dogs/tips/collars.html http://www.humanesociety.org/animals/dogs/tips/collars.html Humane Society: Dog Collars The Humane Society of the United States: Dog Collars Humane Society of the United States: Dog Collars Humane Society: Collars this article