Compared with collars , harnesses allow owners more control over their dogs and can be more suitable for use in canine sports , but if they distort the usual range of motion , they can create repetitive strain injuries [ 6 ] .
Vertical ground reaction forces and stride length have been measured for dogs in a collar or harness , and showed no significant differences , although signs similar to unilateral lameness were seen in dogs wearing harnesses of a variety of styles when force was applied on the lead , as is usual during dog walks , canine sports or guide dog duty . This indicates that either collars should be used , or a harness should be selected carefully [ 7 ] .
Electric collars ( e-collars ) use negative reinforcement to control a dog , as do prong or pinch collars , the use of all of which should be discouraged in the general population . Fear-based control methods such as these elicit more fearful behaviours in dogs than the use of verbal cues , and they lower walk satisfaction for owners [ 2 ] .
Head collars and halters
Head collars frequently require the dog to be desensitised to them , as they elicit behaviours such as nose pawing and face rubbing in an attempt to remove the device . However , these behaviours reduce within 6 weeks of use , so they may be largely due to novelty [ 2 ] .
Head collars have no discernible impact on a dog ' s behavioural expression , compared with neck collars [ 3 ] , and no significant differences in dogs ' behaviour were found in trials of different brands of head collar [ 8 ] .
Chest harnesses
Chest harnesses ( Figure 2 ) are classed as restrictive devices , due to the chest strap at or below the point of the scapula . They often cause significantly altered truncal motion [ 6 ] and may also inhibit movement of the spine at one or more points , regardless of their shape or materials [ 9 – 11 ] .
Guide dog harnesses with chest straps are designed for long-term use and have changed little since their introduction . As with harnesses worn by pet dogs when walking or exercising , guide dog harnesses are usually removed when the animal is at rest .
In a study of three styles of guide dog harnesses [ 9 ] , all were observed to apply pressure and loading forces to both the left and right sternum , as well as variable loading at the shoulders . The loading was found to be significantly higher in the right sternum , which was deemed to be due to the consistent orientation that is required for a dog to train and function as a guide dog .
Figure 2 . An example of a chest harness .
48 Veterinary Nursing Journal