By Emma Fretwell
The dreaded shoulder injuries!
In the wet slippery weather, these injuries are prolific, as well as the tendency we have to get the shiny laminate floors at home. Any sideways slip from the dog specifically in the front legs, creates all sorts of problems, and random lamenesses.
My own dog Damson tripped recently in the wet grass, her left front leg went sideways, and she squeaked a little at the time. She looked fine, and we needed to get home from the furthest point of the walk. She slipped again in the mud as we got closer to home, and properly vocalised this time, her left front leg giving way under her.
I picked her up and carried her home. On examination in the warm and dry, she had excessive range of motion in the middle region of the shoulder, so rest and laser ensued until we could get an appointment for more investigations.
The dog doesn’t have a collar bone, therefore the only attachment point for the front limb is via muscle, tendon and ligament complexes. The front limb of the dog is designed to take the concussive forces that the dog applies to itself – twisting and turning through undergrowth, chasing critters, the jobs we give them – agility obedience and other sports, repetitive training and exercises, sniffing out distinctive smells etc. It will jump and leap about, and the front end is designed to take these forces, tendons will stretch to absorb the forces, and then contract again to transmit the power onwards.
The dog will instinctively follow its nose and so the front legs will follow wherever the nose / head has moved. These front legs are pretty much the only thing that will keep the whole forelimb section of the body off the floor.
The front legs have a pendulum action, the centre of the movement is 1/3 way down the shoulder blade, and the rest of the limb should swing easily back and forth. There are many muscles and groups of muscles in this region, mainly due to the lack of collar bone, all facilitating correct function and preventing abnormal movement.
Due to this lack of mechanical evolution, there is no real stability mechanisms to help the dog when the limbs go sideways instead of forward and backwards, and hence the injuries occur.
There is one big ligamentous structure between the internal shoulder joint and the chest wall, this is the glenohumeral ligament (GH). This just about the only structure that will prevent the lateral movement of the forelimb. Many of the other muscles in this area have other jobs to do, and seem to limit lateral movement as a secondary role. The ligament, therefore has a primary role to stabilise the shoulder (glenohumeral joint), and the muscles have a secondary role in this action too, there are no prime movers or stabilisers to this action.
As a consequence, many medial shoulder injuries will be involving the GH ligament, and the secondary muscles underneath the scapular or shoulder blade, making them very difficult to get to, and to diagnose well.
However Rachel, our vet and director, has found a great way of utilising the MRI for this very reason. The initial scan is of the shoulder region, then the dog is repositioned in the scanner and contrast dye is injected, then the dog is rescanned, and the images are compared. This will show any swelling, effusion or distension in the GH ligament and the joint itself, as well as any issues in the muscles in this area.
Depending on the severity of the problems found on MRI, there are many different treatment options. The more severe injuries require these kind of interventions: gold standard would be stem cells: fat and blood harvested from the dog, sent to the lab to grow the stem cells, and then injected back into the ligament, muscles and shoulder joint, plus a period of rehabilitation to get back to strength and fitness. The silver standard, and no less effective, is platelet rich plasma; blood is taken from the dog, spun down in house and the platelets and plasma are extracted from the blood, and injected back into the areas of concern, plus the usual period of rehab. The more conservative options would be shockwave, laser and rehabilitation, and these would be appropriate for mild cases of medial shoulder injuries.
Teasle, Rachel’s dog, had a recent Medial Shoulder Injury. He presented with some very subtle signs of discomfort, and 2-3 episodes of lameness just for a day or so, but has some odd stiffness and altered movement patterns that were not his usual gait patterning. His examination showed excessive lateral shoulder movement, and odd passive range of motion patterns, and showed signs of pain on palpation in this area. He had the MRI to diagnose the source of the pain and odd patterns, revealing a tear in the GH ligament and muscular tears in the underside of the shoulder blade. He had the stem cells therapy, followed a course of rehabilitation, and returned to full health, he was faster than he has been for years, as well as being cheekier and offering play behaviours that he hadn’t done in a long time!
Damson’s diagnosis was a mild medial shoulder injury, which resolved very well with laser and shockwave, followed by a course of rehabilitation, and we are pleased as she is as right as rain again now too!
If your dog is showing signs of pain, licking in certain areas, limping or lameness, even if it is subtle and just for a day or so at a time, then please do get in touch. You are your dog’s ambassador, and they rely on you to stand up for them to get the right treatment.
