Clean Run - June 2015 - 11

Low Back
Pain

in the Canine Athlete

© ISTOcK PHOTO

By Ryan Gallagher, DVM, Diplomate, ACVIM (Neurology)
Photos courtesy of VOSM except where noted

Low back pain (sciatica) is a common
cause of substandard performance in
canine athletes. It can often be difficult
to pinpoint due to the nebulous nature
of the signs seen, but it is an important
differential for any canine athlete that
is having an unexplained drop in performance or pain referable to their hind
end. Any hind limb lameness in an agility competitor, however subtle, usually
warrants a visit to a veterinary specialist, most often beginning with a sports
trainer or orthopedist to begin the
process of diagnosing the cause of the
lameness or discomfort. In some cases,
this hind limb lameness can be contributed to a back injury, as other orthopedic and soft tissue causes are ruled out.
As part of your dog's examination, a
neurologic examination (or referral to a
veterinary neurologist), should be performed to address any possible spinal
causes of lameness or discomfort.

articulates with the sacrum, which is three fused vertebrae that make up part of the
pelvis. The lumbosacral junction is unique in that it undergoes a large amount of
movement compared to other areas of the spine. As the primary connection of the
pelvis to the rest of the spine, any dynamic movement incorporating the hind limbs
(running, jumping) puts the lumbosacral junction through a full range of motion.

Anatomy

Conditions

Somewhat simplistically, the vertebral
column can be thought of as a tube
of bone that the spinal cord and nerve
roots pass through until exiting and
traveling to various parts of the body
to perform their function. Each individual vertebrae makes up a portion
of this tube, and in between each vertebrae there are intervertebral discs
which function as cushions or shock
absorbers. The lumbosacral junction is
where the seventh lumbar vertebrae

Lumbosacral disease (lumbosacral syndrome, lumbosacral stenosis, cauda equina
syndrome) refers to a number of different changes in the low lumbar spine which all
contribute to vertebral canal narrowing and nerve root compression. These changes can be seen as a primary degenerative "wear and tear" type process in canine
athletes, although certain breeds (German Shepherds and related breeds) do have
a clearly identified predisposition to instability at the site. German Shepherds are
eight times as likely to develop degenerative changes at their lumbosacral junction
compared to other breeds. While not having as clearly defined predisposition as
German Shepherds, the condition does also occur commonly in Border Collies and
Labrador Retrievers. The changes seen with lumbosacral disease include misalignment of the vertebrae (subluxation), degeneration and bulging of the intervertebral disc, and thickening of the bone and soft tissues/ligaments of the lumbosacral

June 15

|

Clean Run

Clinical Signs
The severity of signs in dogs with low back pain/nerve root compression can vary
quite a bit depending on the severity of compression, time of onset, and intended activities of the animal. In early cases of back pain in agility dogs, declining to
jump, missing jumps, and nebulous unilateral or bilateral pelvic limb lameness are
a frequent manifestation of low back pain. Discomfort associated with nerve compression can be quite severe compared with other causes of lameness, with dogs
favoring or refusing to use the limb, even though orthopedically the limb is sound.
In advanced or severe cases of canine back pain, hind limb weakness (dropped in
the hocks), incoordination, weakness of the tail, and even urinary/fecal incontinence can manifest. Even in severe cases, the inability to walk is uncommon, which
can sometimes make it easy to underestimate how compressed the nerve roots
are compared to other spinal conditions. At examination for hind limb lameness
or back pain, your veterinary specialist should perform a complete evaluation that
includes physical, orthopedic, neurologic examinations, and possible imaging options. These tools will give your veterinary specialist a full picture of the cause of
hind limb lameness, discomfort, or back pain.

11
Clean Run - June 2015

Table of Contents for the Digital Edition of Clean Run - June 2015
