Tests of Forces Acting on Collars and Harnesses for Dogs Tests of Forces Acting on Collars and Harnesses for Dogs | HBM

Hartpury College Research Takes the Pressure Off Dog Walking with HBM Miniature Load Cell

Hartpury College & University Centre recently conducted an important study about canine gait analysis and the force exerted on the lead when the canine is either wearing a collar or a harness. The force of the different forms of harnesses dogs wear has the potential to cause new medical conditions or aggravate pre-existing conditions. To find the answer to help relieve unnecessary pressure or force felt by canines during walking, HBM supplied the study with electric strain gauges and software.

The study observed the effects, such as the pressure and force felt by dogs when wearing either a collar or a harness on a lead. Dogs are popular pets in the UK; up to 24% of households own them as pets. Furthermore, domestic dogs play a wide range of roles such as companion dogs, working dogs that perform jobs such as livestock herders, guide or assistance dogs, as well as detection and security dogs. Hence, it is important for dog owners to utilize the array of equipment available, such as collars and harnesses, to help them in fulfilling these roles. Not only is it necessary to do so but also a legal requirement to restrain dogs when out in public, most popularly with a collar and lead or a harness and lead. The restraints, as required by law, provide the dog with the ability to move freely without pain while giving their handlers control over it. However, it does not account for any unseen or unaccounted force that the animal might be facing.

Because of the additional legal requirement for identity tags when canines are out in public, most dogs in the UK wear a neck collar. With this popular type of restraint, a lead is typically connected to the collar using a D ring. The biggest concern raised about this method is regarding possible damage to the trachea and the neck of the dog.

Another popular type of restraint used is a harness, which is available in a range of styles, and head collars, which are similar to the halters used for horses. The head collar is designed to loop under the muzzle and a lead is connected from there—this works by impacting the position of the other straps, thus allowing the handler to have complete control.

Problem

Identify the force that is applied by different types of leashes and how it affects the animal.

Solution

As part of its research to identify whether there is a significant difference in the gait of a dog when it is exercised using either a collar or a harness and to analyze the degree of force exerted on the lead by the handler and the dog, Hartpury College specified the U9C miniature load cell series from HBM to collect data on the amount of force experienced at the site of the dog’s restraint.

Results

The results collated from the study proved, with respect to the particular types of collars and harnesses used in the study, that there is no difference in the gait when the dog is walking or trotting in a harness. However, it did show that the force exerted on the neck and throat when wearing a collar is more localized, with the potential to cause damage or exacerbate existing injuries, while the force exerted when wearing a harness is distributed over a larger area, hence reducing the impact of the force. The data collected can be used by concerned pet owners to make a more educated decision.

Measuring leash strength

dog_leash

U9C force sensors

U9C

catman Data Acquisition Software

catman_software

Potential dangers of excessive forces from collars

Dog owners usually share an extremely close relationship with their pets, and hence would be interested in knowing that dog injuries can occur due to the constant force exerted by collars or harnesses.

Prong collars or choke chains have the potential, as a result of excessive force, to cause mechanical or ischemic damage to the brain, thyroid, trachea, larynx and esophagus. The propensity for increased intraocular pressure due to excessive compression on the jugular vein is also present.

Although considered kinder for animals, there is limited evidence available about the injuries caused to areas such as front limbs, chest or across back due to the amount of force applied by harnesses. It has also been anecdotally suggested that a harness changes the natural gait of a dog.

As a result of that, it is equally important for dog owners to be aware of the potential problems that their dogs might face, such as undue pressure and force on their bodies and joints, injuries, and even chaffing, due to ill-fitting harnesses.

With these important warnings in mind and no concrete information available on how these restraints affect the gait of a dog or the force exerted when in motion and most importantly which type of restraint is better, HBM supplied the key piece of equipment which could help solve the puzzle.

Analyzing the degree of forces excerted on the lead

To identify whether there is a significant difference in the gait of a dog when it is exercised using either a collar or a harness and to analyze the degree of force exerted on the lead by the handler and the dog, Hartpury College specified the U9C miniature load cells from HBM to collect data on the amount of force experienced at the site of the dog’s restraint.

The compact and cost-effective U9C series reliably measures tensile and compressive force where space is a constraint, which was a key consideration in these trials. Enabling dynamic and static measurement tasks to be solved, its high fundamental frequency also makes it suitable for very fast measurements. Manufactured in stainless steel and featuring a welded design, the U9C is a robust sensor, which was the ideal choice for such a challenging application.

By incorporating strain gauges onto the dog’s harness and lead, Hartpury College were successfully able to achieve the desired measurements for both the dog and the handler. To make the design more robust, the transducer was sewn into a one meter lined fleece that enabled the gauge to be fixed to the D ring of the collar or harness. This gauge was then connected to a four port express DAQ connected via USB to a laptop.

The software for analysis, also supplied by HBM, provided the data from both the handler and the dog in numeric data (Hz) pull from each of the trials as well as in graph form. Suitable for challenging applications, catman data acquisition software, which allows data visualization, analysis and storage during the measurement and reporting process, enabled the raw data to be transferred to a spreadsheet and to be analyzed with the SPSS statistical analysis software.

With the strain gauge and the lead attached to the collar, the handlers walked and trotted dogs, and the process was then repeated with dogs wearing a harness instead.

The result

The results collated from the study proved that when using the particular types of collars and harnesses used in the study, there is no difference in gait when the dog is walking or trotting in a harness. It also proved that the force exerted to the neck and throat when wearing a collar is more localized and has the potential to cause damage or exacerbate existing injuries, while the force exerted when wearing a harness is distributed over a larger area, which reduces the impact of the force. The data collected can be used by concerned pet owners to make a more educated decision regarding their dogs.