06/09/2023
Supported by science - dog harnesses 🐶
I was recently approached by a trainer Haigh Hounds asking which harnesses are best for dogs - especially those who pull the lead, so here is the science.
Harnesses are often used as a training aid. Due to dogs likeliness to be unruly at younger ages it is plausible that harness type could have an effect on development. This raises questions to the suitability to the types of harnesses used, especially with younger or more unruly dogs who are likely to apply increased pressure to the harness.
The most prevalent musculoskeletal disease in dogs is degenerative joint disease. Incorrect biomechanics will lead to a loss of joint confirmation and function throughout the body, resulting in abnormal wear, inflammation, and arthritic conditions. With this in mind if harnesses do impact a dog’s natural gait, they may be a contributing factor to degenerative conditions.
Several studies have found altered biomechanics in a variety of guide dog harnesses. These studies have found that the placement of the handle (how laterally the handle inserted on the harness) had the biggest effect on thoracic limb biomechanics. As this is not relatable to most pet owners, these findings lack external validity to harnesses purchased publicly.
Lafuente et al., (2018) investigated the effects of harnesses on shoulder extension in dogs at walk and trot with a lead attached to the centre of the harnesses; furthermore the effects of additional pressure applied to the harness were investigated – providing the highest external validity to pet owners.
At walk shoulder extension without a harness ranged from 128° - 150°, providing an average of 135°. The most restriction was found in a Y-harness with an average of 130° of shoulder extension with the Norwegian harness faring better at an average shoulder extension of 132°. At a trot shoulder extension increased to 144° without a harness, decreased to 139° with a Norwegian harness and a further decrease to 134° with a Y-harness. The most applicable information came when weight was added to the lead to mimic the dog pulling. The Norwegian harness shoulder extension was increased by 1° when weight was applied to the lead whereas the Y-harness decreased shoulder extension by 1° when weight was applied. This finding is interesting as Y-harnesses are often marketed as ‘non-restrictive’ and whilst both types of harness have been proved to decrease shoulder range of movement, the Y-harness proved to be the most restrictive – especially when pressure is added, reducing shoulder extension by 11°!
The reasons for Y-harnesses showing the most restriction has not been investigated, although the positioning of the Y-harness could affect the thoracic sling musculature and brachial plexus resulting in a restriction to muscle activation and therefore limb protraction. The effects of pressure applied to the thoracic sling has been documented in horses, and a reduction in limb protraction, and carple flexion was found by Murray et al. (2013) supporting this hypothesis.
⬇️⬇️Take a look at the studies here ⬇️⬇️
Knights, H. and Williams, J., 2021. The influence of three working harnesses on thoracic limb kinematics and stride length at walk in assistance dogs. Journal of Veterinary Behavior, 45, pp.16-24.
Lafuente, M.P., Provis, L. and Schmalz, E.A., 2019. Effects of restrictive and non‐restrictive harnesses on shoulder extension in dogs at walk and trot. Veterinary Record, 184(2), pp.64-64.
Murray, R., Guire, R., Fisher, M. and Fairfax, V., 2013. Girth pressure measurements reveal high peak pressures that can be avoided using an alternative girth design that also results in increased limb protraction and flexion in the swing phase. The Veterinary Journal, 198(1), pp.92-97.
