The canine athlete can present uncommon challenges to the general
practitioner. If the pet owner is only interested in companionship, minimal
stress will be put upon the body. As the athletic demands of the owner
increase there is a proportional increase in the physical demands placed
upon the animal's body. These increased demands placed upon the animal
introduce a higher risk of injury.
There are four conditions that can impede performance: 1) pain, 2) fatigue,
3) depressed psychology (drive), and 4) impaired health status. In general
most canine athletes are healthy, but their health status should be checked
at least once a year. In healthy dogs their drive to perform is both inherited
and/or acquired through a good training program. A good training program
will maintain the conditioning level of the dog at a level that should
eliminate the effects of fatigue. Pain is the most common cause of performance
impairment and should be analyzed first. Minor pain that does not induce
a lameness can show symptoms similar to the problems seen with fatigue
or drive. Major pain will inhibit performance.
Motion is the one common component of all athletic competition. Motion
is a result of nerves stimulating muscle to move bone. Abnormal motion
occurs when this chain of events is disrupted. Locomotion of an animal
is described as its gait. The walk, trot, and gallop are three forms of
gait. Gait analysis is used to assess the movement of each of the individual
joints and how this movement affects locomotion.
The canine structure is divided into segments when analyzing motion.
The axial vertebral column is made up of many joints and is divided into
anatomical segments. The cranial segment is the head, followed caudally
by the neck (cervical), thoracic, abdominal (lumbo-sacral), and tail. The
appendicular segments are the front legs and the back legs. These are subdivided
into smaller segments by the leg joints: shoulder, elbow, carpus, hip,
stifle, tarsus & phalanges. Locomotion as a whole is a result of the
individual movements of these segments.
Dogs and horses have the ability to minimize pain by altering movement
in such a way that the abnormality may be unnoticeable. This ability allows
subclinical pain to go unnoticed by the trainers, and handlers. Computer-assisted
videographic (CAV) gait analysis can be used to assess to what extent minor
pain has an effect on the musculoskeletal system as a whole. In a normal
trot the movements of the body are symmetrical. This means that the movements
of one side of the body mirror the movements of the other side (Figure
1a). A minor "sprain" of the right carpus not only creates an alteration
in the movement of the right carpus but also the left hip and left tarsus
(Figure 1b). The back, or axial skeleton, is also affected, since it is
the frame through which this alteration is transferred. This can initiate
two problems in the athletic or working animal, one biomechanical and the
other psychological. First, due to the high activity level of the athletic
animal, this alteration caused by the primary injury can lead to secondary
and tertiary pain or injuries in the back or other limbs. Secondly, it
can create a loss in psychological drive. The dog might begin to associate
pain with its workouts.
Trainers and handlers should include lameness examinations in their
training and conditioning programs. A lameness examination includes visual
gait analysis and physical palpation. Visual gait evaluation can be done
once a week or once every two weeks, this allows for early lameness detection.
If a gait alteration is detected, the dog should be referred to a veterinarian
for a physical examination and definitive diagnosis. Rehabilitation time
is relative to the level of injury and the chronicity of the injury. The
longer a lameness goes undetected the longer it takes to recover from the
body's adaptations.
Subjective gait analysis is the most common diagnostic tool to assess
lameness. It starts by observing the animal while it is at rest, looking
for conformational abnormalities or abnormal stances. For example, does
the dog seem to hold one leg up or put most of its body weight on a particular
leg. After these observations are noted the animal is analyzed while moving.
The trot is the best gait to use for analysis, it gives the best picture
of abnormal gait. If one of the segments is impaired the gait will be out
of balance. The patient is observed moving in a straight line toward and
then moving away from the evaluator. Next the dog should be assessed moving
in a straight line from the right side and then the left side. Then it
should be observed moving in a circle, once clockwise then counter-clockwise.
Most gait abnormalities can be detected with subjective gait analysis.
A dog with a lesion causing severe sharp constant pain will carry the limb
and keep the weight off it when lying down. A dull aching pain will produce
a limp during the gait analysis. A lesion that produces a small pain that
occurs in certain phases of locomotion allows the dog to adjust their gait
for relief. This altered gait can lead to subsequent orthopedic problems.
Pain is an important performance inhibitor. When compared to the active
dog, subclinical pain of the companion pet does not greatly affect the
musculoskeletal system. Usually anti-inflammatory therapy is sufficient.
In the physically active or competitive animal any pain or lameness should
be addressed as soon as possible before these problems affect performance.
Gait analysis and physical examination are two useful diagnostic tools
for the trainers and veterinarians working with the animal athlete.
