26 Mar 2017
A few days ago, I saw a 3 year old intact female border collie with a 2 week history of rear end weakness after heavy work. On exam, I could not elicit pain anywhere, but did find a subtle weakness on the right rear. I did some acupuncture and laser. The following day reg vet did rads and bloodwork. Anaplasma positive, but also spondylosis of T12-13, L1-2, L2-3. I'm suspecting (hoping) the symptoms were related to the anaplasma, but I am concerned about the presence of spondylosis in such a young dog. The owner is a vet tech and knowledgeable about conditioning, proper warm ups, avoids ball retrieves, etc. The dog goes on off lead woods walks several times per week, and is in great body condition. There are several other dogs in the household, but from what I understand, they don't have overly rough play. This is an active dog, but not over the top like some BC's can be.
Any thoughts about why such a young fit dog would be developing spondylosis? And ideas on preventing further progression? My thought is core work, but I'm certain that's already being done.
Okay... so my thoughts about spondylosis. It's a topic I bring up in my Manual Therapy for the Canine Spine courses all the time!
So, the thoracolumbar junction is a transition zone in regards to freedom of movement and what the shape of the facet joints will allow. The thoracic spine has horizontal facets, which allow freedom of movement into flexion, extension, side bending, and rotation... save for the ribs and ligamentous support to moderate mobility, it's a 'party all the time' up there! From T11 caudally, the facets are more vertically oriented, and there are also accessory processes down to L3/4 which limit motion to flexion & extension (primarily). You can get some degrees of side bend & rotation if the spine is flexed, but otherwise, that's not what the joints are built to allow.
Here's the issue: In any transition zone, there is an imperfect transference of load from one area to another and those guys (i.e. the facets in this case) in the transition zone take a bashing. This can cause remodelling of the facets. What has been observed (research of Breit, Knaus, & Kunzel), is that with exaggerated or repetitive loading into extension or ventrally, the facets will extend themselves and create caudal and ventral facet joint extensions. When you have facet joints not only medio-laterally, but also caudally, and ventrally, you end up with a type of 'ball and socket joint'. In this scenario, the spine has a significant reduction in stability. Muscles and ligaments are what is left to stabilize... but as you know, a dog can exert a ton of force and motion through the spine with running, jumping, playing etc. So, MY THEORY, is that the NEXT things that occurs is spondylosis as a way for the body to stabilize the joints.
As far as border collies go, I am more surprised NOT to see spondylosis in a dog over the age of 8. When the condition started to occur, I don't know, but maybe 3 is not crazy at all! We start to see degeneration, etc in human spines as early as our 20's... so 3 in a border collie might not be alarming. How many 3-year old border collies get x-rayed?
So, you might not be able to stop further progression... what I would want to stop is degeneration of the discs at sites adjacent to the spondylosis, and at the lumbosacral junction in particular. My best suggestion would be routine traction of the back - standing one-man traction and tail pulls. From a therapy perspective, I would recommend a maintenance regimen of other manual therapies (mobilizations, myofascial release, & massage), acupuncture, and laser for the spine. It sounds like the dog likely already has a great core. Test it with the rear leg slide test (look for a drop of the pelvis) to see if the motor control & timing is off, and treat that if you find it to be problematic. See this video:
All in all, I'd tell the owner not to panic. You have a rationale and now a plan!
I hope this helps!
Members can watch Video Training 13 & 16 for instruction on traction & motor control & timing.
19 Mar 2017
Laurie Edge-Hughes, BScPT, MAnimSt, CAFCI, CCRT
This blog is by special request… this is for you, Dr. Carole Nicholson, DVM, CCRT, CVSMT. An analysis of the paper:
The magnitude of muscular activation of four canine forelimb muscles in dogs performing two agility-specific tasks
Kimberley L. Cullen, James P. Dickey, Stephen H. M. Brown, Stephanie G. Nykamp, Leah R. Bent, Jeffrey J. Thomason and Noël M. M. Moens
BMC Veterinary Research, 2017, 13:68
Background: The purpose of this study was to measure the muscular activation in four forelimb muscles while dogs performed agility tasks (i.e., jumping and A-frame) and to provide insight into potential relationships between level of muscular activation and risk of injury. Muscle activation in eight healthy, client-owned agility dogs was measured using ultrasound-guided fine-wire electromyography of four specific forelimb muscles: Biceps Brachii, Supraspinatus, Infraspinatus, and Triceps Brachii – Long Head, while dogs performed a two jump sequence and while dogs ascended and descended an A-frame obstacle at two different competition heights.
Results: The peak muscle activations during these agility tasks were between 1.7 and 10.6 fold greater than walking. Jumping required higher levels of muscle activation compared to ascending and descending an A-frame, for all muscles of interest. There was no significant difference in muscle activation between the two A-frame heights.
Conclusions: Compared to walking, all of the muscles were activated at high levels during the agility tasks and our findings indicate that jumping is an especially demanding activity for dogs in agility. This information is broadly relevant to understanding the pathophysiology of forelimb injuries related to canine athletic activity.
So firstly, when doing my Master’s Degree, and being trained to critically evaluate research, we were tasked with looking at papers to decide, ‘Is this research that matters?’ There is a great deal of research out there that is research for research’s sake. Additionally, I remember being terribly frustrated, as a clinician, trying to choose a research topic that was ‘doable’ and ‘provable’ and ‘narrow-enough’ that it could be a single research project. Easier said than done! As clinicians, we want research that makes a difference to us clinically, however, all of the pre-clinical / academic research that leads to clinical research needs to be put in place first. This is one of those papers. In fact, one line in the paper summed up this thought: “…the state of the art for analysis of fundamental biomechanics in canines is decades behind human and equine science.”
Now, that being said, what were the golden nuggets from this paper?
- Dogs activate their Biceps (BB), Supraspinatus (SP), Infraspinatus (IF), and Long Head of Triceps (LHT) more during jumping or going over an A-frame as compared to walking. (This may seem obvious, but without research to validate, it is an assumption. Again, foundational research to base further research upon.)
- Ascending the A-frame saw the greatest muscle activation occurring during swing phase of the stride.
- Ascending the A-frame was where Infraspinatus had the greatest activation.
- Other muscles were activated during ascending, but less than IS.
- Descending the A-frame revealed the greatest muscle activation occurred during the stance phase of stride.
- Supraspinatus had the highest muscle activation while leaving the A-frame (after descending). Descending the A-frame had the second highest activation for SP.
JUMPING (And for the record I found the different phases of the jump to be poorly defined and confusing. They were not broken down enough to be entirely useful data.)
- All muscles showed a peak activation at:
- swing phase (i.e. early take off?)
- Early stance (i.e. landing?)
- Mid swing (i.e. going over the jump?)
- Long head of Triceps as well as the Biceps had the highest activation at the early take off phase of a jump.
- For supraspinatus, jumping (i.e. going over the jump) yielded the second highest activation, akin to descending the A-frame, for this muscle.
The clinical relevance of this paper
Does this paper tell us why injuries occur on these pieces of equipment or to which muscles?
Does this paper guide our clinical decision making?
What is the only fair clinical hypothesis we can take away from this paper as Rehabilitation Professionals?
Be sure to retrain jumping tasks and ascending-descending tasks during your rehabilitation of the Surpraspinatus, Biceps Brachii, Infraspinatus, or Long Head of Triceps injuries in an agility dog.
Is this paper a stepping stone for future research?
YES, and maybe that’s where we leave it.
There you have it! I know you were hoping for more, but any other interpretations would be mere speculation and reading into the paper what isn’t really there.