Alarming facts from a recent survey :
63% of the dogs examined had neck and spinal injuries.
78% of the dogs with aggression or over activity problems had neck and spinal injuries.
Of the dogs with neck injuries, 91% had experienced hard jerks on a leash or had strained against their leashes.
The study concludes that leash corrections, the dog forging ahead or a tethered pet hitting the end of a solid line may inflict spinal injury.
Excerpts from the above mentioned survey:
“During 1992 several Chiropractors, my students and I conducted a study of 400 dogs from different dog clubs in Sweden. Dog owners were offered a free examination of their dog by a chiropractor in return for their voluntary participation.
Those who volunteered to participate in the study had mostly ordinary dogs, in that owners presented them to us without any suspicion of spinal anomalies…Canine back problems are common. The result of our study showed that the chiropractors found back anomalies in 63% of the 400 dogs…dogs that “acted out” in other words, that exhibited over activity and aggression, 78% had spinal anomalies. Spinal anomalies seem to constitute an irritation that often results in stress reactions, aggression or fear. This is also in accordance with my own and my students’ experience with problematic dogs... In our study there were some factors that correlated with spinal anomalies. These were:
Pulling on leash (see explanation below).
Limping during adolescence.
Pulling on leash:
Of those dogs that had cervical (neck) anomalies, 91% (!) had been exposed to harsh jerks on the leash, or they had a long history of pulling or straining at the end of a leash. There is a risk of "whip-lash" from jerking the leash that probably increases if the dog wears a choke chain. Choke chains are constructed such that pulling it results in pressure distributed around the dog's neck, but the muscles that absorb the pressure are situated mostly at the sides of the neck. The neck and throat are almost unprotected.
Choke chains can be dangerous. For many years I and others have criticized the use of choke chains and training methods that use jerking and pulling on a leash as a means of controlling behavior. Unfortunately, most dog trainers use just this technique. There is probably a relationship between the force of the jerk and the risk of injury. I believe dog owners should be warned that chaining a dog to anything firm, that isn't elastic, without surveillance may increase the risk of a spinal injury. A dog can easily forget the boundaries of the chain or rope, accelerate, and suddenly come to a halt, with all the stopping power concentrated around the dog's neck.
Hallgren , “Animal Behavior Consultants Newsletter” July, 1992, V.9 No.2.