From the Canine Arthritis Management Team: On Throwing Balls

Guest article from the team at Canine Arthritis Management:

Hannah Capon, MA Vet MB MRCVS

Danielle Pountain, RVN dip AVN dip HE CVN Cert SA hydro

Lynsey Tindall, RVN dip AVN

Rebecca Barr, BVMS MSc Behaviour MRCVS

Melanie Bruder, DipCOT, Post Grad Cert(Small Animal Rehabilitation)

The team at Canine Arthritis Management (CAM) can often be heard telling owners that ball throwing is not an ideal activity for their arthritic dog. In fact, CAM would go as far as to say that it is not an ideal activity for any dog, whatever their age or condition. Here, three team members look at the impact of throwing a ball on a dog, both physically and mentally.

The Physiotherapist

Many dogs derive a great deal of pleasure from chasing a ball, and many owners undoubtedly derive pleasure from throwing a ball and watching their dog having fun.

What many owners don’t realize, however, is that this activity may not be as beneficial as it seems, and in dogs with underlying conditions such as arthritis, this activity is likely to cause harm.

In order to understand why we recommend that dogs with arthritis and other musculoskeletal conditions do not chase balls, it’s necessary to understand a little about both the musculoskeletal system of the dog as well as the behavioral aspects of this activity.

How dogs move

Dogs, like other quadrupeds, tend to move forward in straight lines and lack the rotatory aspect of bi-pedal movement. Their fore and hind limbs are developed to fulfill specific functions. The hind limbs act as the ‘motor’ for the dog, propelling them forward, and the forelimbs act primarily as the braking and shock absorbing system for the dog. Dogs have developed light, long limbs powered by strong muscles around the hips, spine and shoulder girdles.  Power is transmitted from the back legs along the spine to propel the dog forward. They carry about 60% of their weight through their front legs and 40% through their hind legs.

In order to allow dogs to move efficiently by taking long strides, they have sacrificed stability at their shoulder joints so that the dogs’ front limbs have no bony attachment to the skeleton. Humans also have very shallow shoulder joints but they do have a bony attachment by way of their clavicle or ‘collar bone’.

What this means is that the dog’s forelimbs are attached to the dog only by a group of muscles known as the thoracic sling and, at the same time, they are also supporting most of the weight of the dog.

During movement, the dog has both internal and external forces acting on them by way of the mass of the dog to the ground, as well as forces exerted by muscles and ligaments. Movement is also affected by the dog’s own confirmation, the surface that it is on, and the restraints it may be using.

As owners and breeders of dogs, we have influenced the form of our dogs to change their function. While dogs no longer need to hunt down prey or run from attackers, humans have bred them for our own purposes. It is not hard to see that this species has a huge diversity of form, from the sledding breeds who have muscles designed to work at a steady speed over long distances, to greyhounds who have muscles that work efficiently for short sharp bursts of speed. Some dogs have over angulated hind limbs that allow them to take long strides but subsequently have less stability due to the strength required to stabilize their flexed limbs.

How chasing a ball can be harmful

Our dogs have changed both in form and function from their wolf ancestors, so when we ask a dog to run repeatedly from virtually standing to a gallop, brake sharply, often skidding on the underlying surface, throwing their neck back initially, and then bringing all their weight forward as they reach for the ball, often twisting at the same time, we can see that the forces on a dog’s skeleton and muscles are enormous. Increasing speeds can as much as double the forces generated.

It is thought that the most dangerous component of ball chasing occurs during braking, and thus is often responsible for shoulder injuries.

We also know that repeated micro-trauma to muscles and cartilage is the cause of long-term damage and that the older a dog gets, the more likely it is to be carrying small injuries. This will cause a dog to try and compensate, thus further altering the loading of its limbs.

In summary, chasing a ball combines sharp acceleration, high speeds, rapid and uncontrolled deceleration that includes rotatory forces on fundamentally unstable joints. In addition, this activity is usually repeated over and over again.

So, is it never safe to throw a ball? My own opinion is that there are many other activities that your dog can enjoy without throwing balls, however, if you do want to throw a ball I would suggest the following:

  • Never throw a ball for a dog who is injured or has arthritis
  • Only throw a ball once the dog is warmed up
  • Never throw balls indoors, particularly on slippery floors
  • Do not throw balls on wet surfaces or unstable surfaces such as gravel
  • Throw straight and low down
  • Do not throw downhill
  • Do not throw repeatedly
  • Do not throw for more than one dog at the same time

The Myotherapist

Muscles are prone to trauma during high energy activities, such as racing and leaping for a ball. The explosive action that the dog undertakes to chase in a sudden moment uses incredibly powerful propulsive forces. The same forces used to initiate this high-speed activity are experienced in reverse when suddenly breaking and landing. Unpredictable actions involved in these strenuous actions such as breaking, twisting, and landing can result in muscles being put under great stress for which they aren’t designed, or weren’t prepared. Imagine a muscle trying to contract but ripped into extension, or already at full extension but then forced to lengthen more.

It is sadly normal for a dog not to be given the chance to “warm-up” prior to a ball game. Gently exercising prior to high-stress activities “prepares” them for the work ahead and results in less damage, but too often dogs are thrown a ball as soon as they reach the yard or immediately upon getting out of the car. It is common to see owners toss a ball with a ball chucker twenty times and immediately after, for the dog to then go straight back in the car with no cooldown either.

Dogs have four legs and four areas to subtly offload weight, which means they can easily compensate with two or three when first dealing with a minor injury. But dog owners don’t typically notice this subtle transfer of bodyweight and the developing of a muscular imbalance. So the games/ and activities continue, as does the opportunities for further damage.

But once the dog’s body has started to compensate, these overworking tissues are more likely to get damaged in these hazardous activities like chasing balls. Sadly, we often find that the owners can misinterpret their dogs compensated overdeveloped muscles as a sign of health, not realizing that other areas of the dog’s body have correspondingly decreased in bulk and function.

Eventually this ability to shift weight and function fails. The compensatory areas themselves become tense and painful but by this stage, we have multiple areas of concern, all from one “fun” activity.

The Veterinary Behaviourist

Ball throwing is an activity that many dogs and owners engage in on a regular basis. In recent years, concerns have been raised about the mental and physical impact this can have on dogs.

Many dogs get very excited during games of fetch. This increased arousal can involve increased heart rate and adrenaline levels, causing an increase in cortisol levels, and can lead to ‘frantic’ behaviors as a result of reduced impulse control and frustration tolerance.

Adrenaline is designed to be released in short bursts, as a one-off during a chase for example, but by repeatedly throwing the ball means it is released for much longer periods.

Cortisol levels take several days to return to normal (some reports say up to several weeks), and studies have found that prolonged exposure to high cortisol levels can be damaging to long-term health.

Adrenaline and cortisol both play a role in the expression and regulation of behavior. Living with increased levels over a long period of time can be responsible for a number of problematic and dangerous behaviors, including your dog’s inability to ‘switch off’, cope with challenging situations and even show more aggressive behavior.

CAM’s View on Ball Throwing

In summary, you can see why CAM is not an advocate of ball throwing for dogs. The negative physical and mental impact, both long and short term, far outweigh the positive; most of which are only experienced by the dog in the “high” of the moment.

We would always recommend alternatives as a way to exercise and mentally stimulate your dog, and strongly advise that dog owners throw that ball launcher in the trash!

It is important for us all to remember that canine arthritis is a complex, multi-faceted disease. It is considered to be associated with breed predisposition, genetics, body weight, form, function, environment, lifestyle, and nutrition. There are proven risk factors in all mammalian athletes and these are frequently associated with repetitive, high-intensity activities and the substrates upon which these ‘sports’ are undertaken have also been examined in relation to incidence of injury.

It is never the wish of the Canine Arthritis Management team, or that of your veterinarian, to deprive your dog of a fun-filled life. Our goal is to make people aware that dogs are naturally great deceivers, as they are pack animals that instinctively hide vulnerabilities, especially pain.

That’s why identifying chronic pain in dogs continues to pose such a challenge! Our dogs generally have one purpose in life, and that is to offer us unconditional love and respond to our commands/demands in a way that results in rewards and positive interaction.

But unfortunately, it’s often not until our pets reach crisis point, such as demonstrating a limp or showing difficulty transitioning between sit, stand, and lay down that we can see there is a problem. A high-drive dog with significant orthopedic disease and a high pain score on validated scoring systems will continue to perform reward-based tasks. This reward may take many forms and can consist of owner interaction, food, or positive neurochemical and endorphin release. This doesn’t inherently mean the dog is enjoying the activity per se but the consequential effects of such.

How breed differences change how dogs respond to ball throwers

To bring our topic back to ball flingers specifically, we ask you to consider the fact that certain breeds of dog were bred to serve a specific purpose and have subsequently physiologically adapted to do so, while others were bred for pleasing aesthetics and conformational extremes.

The greyhound, for example, is a sprinter, muscular, with light, yet long bone structure, higher red cell concentration, and less body fat per kilogram mass than any other breed. This allows for efficient delivery of oxygen to organs and muscles while minimizing load and impact in joints and also means they have specialized musculoskeletal systems.

Conversely, the Border Collie has a greater range of motion in all joints than healthy Labradors, while also being lighter on their feet with reduced stance phase of locomotion. This allows them to drop and revert from their herding pose rapidly! On the other hand, Dachshunds and Basset Hounds have a significant disproportion between limb and back length, resulting in decreased core stability, a propensity to experience intervertebral disc dehydration and consequently intervertebral disc extrusion.

Dogs can generally be dividing into categories, that of sporting, herding, and protection. This means we see significant differences in power, strength, and athleticism among different breeds. That aside, there is empirical evidence that repetitive high-velocity activities cause unnecessary risk of injury in mammals of all species.

Spinal torsion from leaping into to air to catch a ball has been associated with numerous cases of explosive intervertebral disc extrusion. Research examining the impact on dogs jumping from the back of our modern-day 4×4 cars demonstrates there is approximately 4 times the impact exerted on the limbs and subsequently the joints than of that of a normal step. And we know that abnormal load through a normal joint results in the development of an abnormal joint, but we refuse to accept that asking our dogs to throw themselves into the air to catch a ball is damaging.

There is no need for a blame and guilt culture in the identification and management of canine osteoarthritis. What we need to do, instead, is to foster a supportive, informative, evidence-guided look at the lifestyle choices we make for our canine companions and consider if all of our choices are appropriate based on what we know about the prevalence, signalment, and known established risk factors for disease.

In short, there are many more suitable activities people can undertake with their dogs that don’t pose a significant risk of injury and can contribute to the development of chronic disease.