Rocky Bay Equine Newsletter 
December 2014 
(oops & otherwise)
First off, our sincere apology for the confusion of topic for the November Symposium.

Even with less focus on the cervical spine than we'd anticipated, we hope you were able to appreciate the magnificent design of equine tendons & ligaments. A big "thank you" to everyone who participated.  Dr. Gaughan shared his extensive lameness and surgical expertise on the subject of tendons, what they're made of, how they work and what we've learned (and continue to learn) about how to treat them when bad things happen.  Dr. Weeks made a short follow up presentation focusing on the cervical spine, sharing some relatively new approaches to the diagnosis and treatment of sometimes obscure and often complex musculo-skeletal maladies that can afflict the spine of performance horses.

A "take home" connection between both tendon and spinal topics is advancement in medical imaging methods and applications.  Technology, (like RBE's newest ultrasound equipment) has afforded us amazing insights into the musculoskeletal system, from the extremities to the cervical spine. These insights allow us to recognize and treat problems before they become significant dysfunctions, particularly for  performance horses.

Word of the Month
axial skeleton
"axial" = relating to an axis.
"axis" =  a central structure to which other parts are connected.

The axial skeleton is comprised of the skull, vertebral column, sternum and ribs.  The vertebral column usually contains around 54 bones distributed in cervical- 7, thoracic-18, lumbar- 6, sacral- 5 (fused) & coccigeal-18 segments.  Do you know which breed is notable for bucking these number trends?

We're planning another symposium for February 2015.  We'll continue our exploration of form and function and include an in depth look at chiropractic medicine.

Acupuncture and chiropractic are often the most effective treatment modalities for addressing lumbar back strains. Integrative medicine services are available with Dr. Crystal McRae through RockyBay Equine.
Contact Information
office of
Dr.Bo Weeks
Dr.Crystal McRae (Williams)
    (253) 858-4529
    (360) 876-1544
call these numbers any time for emergency service

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Ahhh, the season of light and giving and hope.  Ironically heralded by black Friday.  Moving on from that less than auspicious beginning and amidst the hoopla of glitz and gluttony we'd like to remember the more uplifting reasons for the season.  We thank you, every one, for letting us serve as your animal health care advisers.  We appreciate your trust, your incredible animals and the privilege of working with you over this eventful Year of the Horse.  May peace, health and well-being warm you on these wintery days and accompany you into the upcoming Year of the Goat. (Whoo-hoo, small ruminants finally get their due!) 
Cheer fully,

Dr. Bo Weeks, Dr. Crystal McRae(Williams), Linda Weeks
and all the toastmasters at RockyBayEquine!
Continuing our exploration of the magnificent design of the equine axial skeleton, lets move on to the thoracolumbar spine. 


the Equine Thoraco-lumbar Spine

Moving caudally along the axial skeleton from the head, the cervical spine connects to the thoracic spine, connects to the lumbar spine, connects to the sacral spine and finally to the coccygeal (tail) vertebrae.  Taken together the thoraco-lumbar spine consists of 18 thoracic vertebrae, their associated ribs and 6 (usually) lumbar vertebrae.  Dorsal processes of the 3rd through 5th thoracic vertebrae form the withers, the ribs complete the thoracic spinal complex.  Shape of the vertebrae changes from tall to wide as it transitions from thoracic to lumbar segments.  That's the basic form, magnificent itself and even more so when you consider function.  Basically, a large elastic band made of strong tendon, ligament and muscle suspends the spinal bridge connecting the horses head to its tail.  The nuchal ligament forms the topline from poll to withers, where the supraspinous ligament and epaxial musculature, the complex of large back muscles, takes over along back & loin.  The major epaxial muscles include the longissimus dorsi (long back muscle - extending from the last cervical vertebrae to the pelvis) the latissimus dorsi (broad back muscle) and the iliocostalis muscle connecting the ribs & pelvis (ileum).  Mechanically this means that when a horse stretches, extending and lowering its head, the back rises and the epaxial (dorsal back) muscles relax.  Back muscles are paired, one set on each side of midline, allowing the back to flex & extend as a unit or, with contraction of one side at a time, allowing lateral flexion and spinal rotation.  Rotation and lateral bending (side to side) occurs primarily in the mid-thoracic spine.  But that's not all, we can't neglect the hypaxial and abdominal muscles, the nefarious "core" when discussing the back!  The rectus abdominus originates at the sternum and inserts on the pelvis.  Contraction of this muscle raises the thoracic and lumbar spine, in effect "rounding" the back.  Weak abdominal muscles allow lumbar vertebrae to sag, increasing strain on the entire back bridging complex of bone, ligament and muscle.  (The same thing happens to us, just in a different orientation.)  Magnificent isn't it!  Magnificent, complex and still not completely understood, we are still learning new things about basic equine anatomy and biomechanics.

What happens when the magnificent design becomes over stressed or malfunctions?  Thoracolumbar dysfunction can be difficult to appreciate and it can be either a cause or effect of gait abnormalities.  Stiffness, resistance and other locomotor or behavioral problems in the horse may also arise from back pain.  Diagnosis requires in depth examination of the animal at rest, in motion and often under saddle.  A thorough knowledge of normal form & function (anatomy & biomechanics) relative to breed, occupation and performance history is vital.  When it comes to diagnosis, technology has again come to our aid.  Radiography, ultrasound, nuclear scintigraphy, thermography and MRI are all valuable tools for collecting information about structural integrity, or lack thereof.   Both acupuncture and chiropractic manipulations may assist with diagnosis and they are often successful for treatment of acute inflammation and for ongoing maintenance of performance horses who are likely to experience overuse injuries.  

A few definitive pathologies that may occur in the thoracolumbar complex include impingement of the dorsal spinous processes of the vertebrae sometimes called "kissing spines".  Often associated with the withers, the problem is less commonly found in other vertebral segments.  Osteoarthritis of the articular processes of the epaxial intervertebral joints (bony changes where muscles & ligaments attach),  muscle strain, spasm, overuse injury and direct trauma can all contribute to back pain.  Saddle induced discomfort is certainly real and can become pathology if it causes localized ischemia (loss of blood supply) in the muscles but it does not directly cause the deeper bony changes that result in chronic back pain.  Truthfully, a definitive diagnosis is often not discovered, sometimes simply due to financial or other practical constraints.  Don't despair, this is where practicing the art of medicine blends with the science of medicine.  Experience and commitment to continuing education, a thorough knowledge of possibilities and probabilities allows the veterinarian to successfully treat your horse even when "probable cause" is the working diagnosis. 

Our next Magnificent Design segment will focus on the twists and turns of the lumbo-sacral spine.  Problems with this highly flexible spinal segment can be a real pain in the sacroiliac.  From sliding stops to airs above the ground, it's all about connection of the hind limb motor to the skeletal framework..... stay tuned!  Also, put February on your calendar for another RBE-CE Symposium.  The topic will continue our focus on form & function and will include the application of chiropractic methodologies. Watch for more information in upcoming newsletters.
When is it ok to look a gift horse in the mouth?
Ho, Ho, Ho!
When you get 10% off of dental work during the month of December of course, Santa says so!
call now to schedule,   253 858-4529 or  360 876-1544
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