There is clear evidence that the use of choke collars can cause a variety of injuries to dogs from head to tail. Similarly, dogs who pull against a lead attached to their collar are at risk from injury.
A dog has seven cervical vertebrae and other critical structures in the neck. The vertebrae protect the delicate spinal cord which carry’s signals throughout the body. A chiropractic study* of 400 dogs thought to be healthy found that 63% had back or neck anomalies and over half of these dogs were reactive or aggressive.
In addition to skeletal damage, lead pulling restricts the blood and lymphatic flow to and from the head causing problems with vision and hearing. It may also impinge the nerves supplying the front legs and lead to abnormal sensation in the feet and subsequent chronic paw licking.
So, what should an owner use? There are many excellent harnesses on the market and lots of advice as to how to teach your dog not to pull using positive reinforcement.