PREVENTING ARTHRITIS

Agility Australia Feb 9th 2002

Hi all,

This is one of my essays, that is probably reaching book size, so grab a cup of coffee, glass of wine or a beer, whatever is your favoured beverage.

Edward asked:
<< Does agility and jumping courses cause premature arthritis in dogs? >>

Bottom line, Edward, is that probably no-one knows (unless this defence force study that Denise mentioned can shed some light - but then again, that was not a study on agility!)

I guess I can start by talking about what is likely to cause arthritis, and I am talking about degenerative joint disease and subsequent osteoarthritis here - not rheumatoid arthritis). Basically, it is trauma to the joints, and this is often old age wear and tear, but dogs that have had an injury that causes instability in a joint (torn ligaments, etc) will
develop premature, or more severe arthritis, as will joints that have a natural instability (e.g. hip dysplasia) or cartilage that has not developed properly (OCD) or joints that do not fit together properly due to a mismatch in bone growth (elbow dysplasia.)

Now, as far as my inquiries have taken me, there are no real studies, of any sort, on "sports injuries" in dogs (other than greyhound racing - where there is a financial interest - dollars drive research!) But my veterinary knowledge leads me to some logical (hopefully) conclusions.

There are concussive forces on joints when a dog lands from a jump, or just running. Several components help absorb these forces: muscles (which contract and stretch well, especially if warmed up and not tired), as well as tendons and ligaments (which do not stretch at all). If the muscles are not functioning properly (they are cold, or tired) then lots of different things can happen. One is pulled muscles. But also, the ligaments must absorb extra force and this can lead to muscle sprains - it may be just a
few fibres within the ligament, or the whole ligament may rupture (such as a cruciate ligament tear, or a sprung toe). There is more compression on joint cartilage and because the nutrition of cartilage is pretty poor (it does not have a blood supply - it depends on joint fluid for oxygen and nutrition) then long term, low grade damage is likely to have permanent effects.

So, what can we do to minimise these effects (assuming they happen!)

1. My first advise would be to keep your dog fit. The fitter the better, because the muscles become better shock absorbers. (Fitness is not just an issue of whether the dog has enough "puff" to run around the agility field at full speed without tiring.)

2. My second would be to advise good warm ups - we may not see effects of running cold immediately - but running with cold muscles may be a component in causing long term, low grade damage to joints.

3. Avoid repetitive jumping, especially at higher jump heights. Repetitive jumping will put more strain on ligaments and joints as the muscles tire. Several short sessions is better than one long session of jumping. I do some warm up work, at lower jump heights. Then I do a short period at full height, or sometimes, above full height to keep muscles conditioned to jumping those heights. If it is an extended training period, I will then take jumps back to a lower height again for the rest of the session

4. As a general rule, we should be jumping lower heights.

Some people would like to quote the previous European study that encouraged higher jump heights. As I have said in previous posts, I do not hold with the theory that higher jumps created steeper take-offs and landings, which in turn creates less "horizontal" force for the dog's legs to absorb. Yes, a flatter jump does create more "horizontal" force but many dogs do not use a more vertical take off the jump higher - they jump both higher and longer. Also, I feel the dogs' body is better designed to absorb horizontal force (otherwise we should never allow our dogs to gallop around a park!) So, I support lower jump heights.

5. Teach your dogs to turn well. If a dog lands then turns on a sixpence with his full weight on the foot, the torsional forces that the ligaments must absorb would be extreme. If, however, the dog has been taught to start to turn during the jump (with early commands), there is less stress on ligaments.

6. Get rid of cleats on obstacles completely. Cleats do not only cause pain by jamming the toes, but the amount of distortion on the feet (that must be accommodated by ligaments and joints) is quite severe. This causes totally unnecessary stress on ligaments.

Now, finally - some anecdotal evidence. (Anecdotal evidence is hearsay - stories about your own personal experience - if there is lots of anecdotal you might suspect that it is true - but it is not scientific proof)

Ned has had 2 or 3 sprung toes, and one episodes of acute cartilage damage requiring 3 months off. He has also had one episode of shoulder tendon inflammation. Now, his sprung toes occurred as acute injuries while playing with tennis balls - he absolutely must get to the ball first and does some awful things to himself to ensure he does so, with lots of really tight, fast, skidding turns. This has probably caused to acute ligament damage, but it is probable that there has been some repetitive low grade sprains to his
toe ligaments that predisposed the problem. His worst cartilage injury occurred at Max Keating's birthday party, when everyone just kept throwing the ball (for hours) and there were lots of dogs competing for it (and Ned nearly always came up with it). This certainly caused the acute injury, but, there may have been some unhealthy cartilage, caused by a lot of jumping and landing on dog walk cleats, in the joint beforehand. There is no way we can know.

He now has quite thickened toes, and has a mild lameness that he warms out of - a bit of arthritis in the toes.

Would I have changed anything - probably not.

I get a pain in one hip, and have a rotator cuff problem in one shoulder which can be quite painful, but there is no way I am giving up agility. And I know of many people with problems worse than mine, and they do not want to give up agility, either. It is just too much fun.

Ned obviously loves the sport. I do not think I can misinterpret that wagging tail and the excitement when we see equipment. I do not throw balls on land for him any more - I put him is a sit stay then send him when the ball has landed. I do not let him compete against other dogs to fetch a ball. We fetch ball in the water so he gets heaps of swimming. We do a fair bit of straight out galloping, but nothing that will make him do a sudden change of direction. So we have adapted.

Some other issues:

Some-one made a comment about cruciate ligament injuries. I doubt if agility would increase the risk of cruciate ligament injuries, unless it is when we throw the ball for the dog at the end, for a reward. Cruciates snap when the dog spins with its hind leg planted firmly on the ground - foot does not rotate so the knee must, and the ligament is overstressed and
snaps. I do not think that agility induces this sort of action, although turning at the fly ball box might. Cruciate ligament injury is the most common orthopaedic complaint in canine veterinary medicine. So this injury happens frequently, even in the average back yard dog. It's importance to the agility athlete is whether he can come back to competition after surgery. My experience is that with good physiotherapy (and good surgery) that dogs can continue to compete. The classic example was Nicola Read's
cattle dog Ruby, who had surgery at about 10 years old and continued to compete until about 12. Even now, she still races around like a maniac.

Denise talked about jumping dogs at an early age and damage to growth plates. This is a totally different issue. Growth plates are not in the joints, and arthritis is, by definition, inflammation of the joints. The one exception to this comment is that elbow dysplasia and subsequent arthritis is caused by a mismatch in the growth of the two bones in the forearm. Jumping and subsequent concussion of a growth place may be one factor in the mismatch of the bone growth. But growth plates close at different times -
slower for large dogs, sooner for small dogs, so setting an absolute age of 18months is not appropriate.

Certainly, jumping a dog too young is not a good thing. Unrelated to the growth plates, we also have to consider growing joint cartilage. Concussive trauma on immature cartilage cannot be a good thing, either. So, the general fitness of the young dog is also relevant, because we know that good muscle condition will help protect tendons, ligaments and cartilage from damage.
The answer to this is to be careful - do less and lower with younger dogs. And Denise is very right is saying you can do a lot of excellent training just working with the uprights, and maybe the poles on the ground.

Yet another issue is back problems - I know of several agility dogs with spondylosis - arthritis of the spine. Now this is also common in the average pet dog, but often does not cause much of a problem. We see it when we radiograph the dog for some other reason - the spondylosis is there, but the dog shows not signs of a sore back.

It is my suspicion (but far from proven fact) that many of these agility dogs with a sore back would have developed spondylosis anyway, but because the dog does agility, it has become painful for them. The average dog does not flex their back very often, but a dog that jumps, weaves and does a-frames certainly uses his back a lot. I do not think this causes the spondylosis, but it makes the spondylosis painful for the dog that, if he were kept in the back yard, would never have noticed he had a problem.

Anyway, I hope this has given everyone something to think about. If anyone wants to discuss any of these issues further, I am more than happy to let you know what I know.

Thankyou, Edward for stimulating the discussion again, after the New Year lull.

Le Hammer BVSc