7-9. Evaluating conscious proprioception.
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While in this position, have the dog hop from side to side by holding the back end and one forelimb up without supporting
all the weight and pushing the animal laterally on the side of the tested limb (Figure 9). This evaluates both conscious proprioception and strength since the weight of the dog is shifted to the tested side. Because
motor function is also evaluated by these manipulations, it will be necessary to support the weight to really evaluate the
proprioception component in a weak animal. When evaluating hopping and placing reactions, poor initiation of the movement
suggests a sensory (proprioceptive) deficit, whereas poor performance of the movement suggests a motor problem.
In cats, conscious proprioception reactions are best evaluated with hopping, wheelbarrowing, and nonvisual tactile placing.
The wheelbarrowing reaction is evaluated by supporting the patient under its abdomen and lifting its hindlimbs so that all
its weight is supported by the forelimbs. A normal animal should be able to walk forward and from side to side. Be careful
not to elevate the hindlimbs too much since it may result in an abnormal body posture. The extensor postural thrust reaction
is somewhat similar and is used to test the hindlimbs. To evaluate it, support the animal by the thorax, just caudal to the
forelimbs, and gently lower it until its hindlimbs touch the floor. A normal animal will move its limbs caudally in a walking
motion as it touches the floor to gain normal support. Nonvisual tactile placing is evaluated by supporting the patient under
the thorax while covering its eyes and bringing the forelimbs (at or distal to the carpus) in contact with the edge of a table,
one at a time. The normal reaction is for the animal to place its foot on the surface of the table immediately after contact
with the table. Be careful not to restrict the patient's movement while testing because it can result in a lack of reaction.
Other factors
As part of the neurologic examination, you should also evaluate the muscle mass of the head, limbs, and trunk. I like to evaluate
the muscle mass while the animal is standing, just before I evaluate conscious proprioception. I also evaluate the muscle
tone of the tail. Any asymmetry is often more informative than a bilateral, symmetric atrophy. Neuropathic atrophy can be
identified as quickly as seven to 10 days after the insult, whereas disuse atrophy will be apparent after a few weeks.
Evaluate deep pain perception in all paralyzed dogs. Deep pain perception is not a reflex, so we want to see a reaction from
the animal (e.g. turns its head, cries, tries to bite). If the superficial pain perception is intact, then the deep pain perception will be
as well. When testing for deep pain perception, apply a strong pressure at the base of the third phalanx with forceps. Limb
flexion is only a reflex (flexor reflex) and should not be interpreted as a sign of positive deep pain perception.
Finish your examination by evaluating the animal for a painful area. For the cervical spine, I find that observation of the
animal and manipulation of the neck are more informative than palpation of the spine (the spine being ventral to a large muscle
mass in that area). Do not move the neck if a spinal fracture or an atlantoaxial instability is suspected. Also, neck manipulation
is not necessary if obvious neck pain is noted on simple observation of the animal (e.g. the pet screams when it moves its neck itself, the pet holds its neck still and looks around by moving its eyes only, or
muscle spasms can be seen in the neck). If there is no risk of fracture or instability and if pain is not evident, gently
move the neck from side to side and up and down and note any pain or resistance. Try to reduce the stress of the patient by
talking or rubbing its ears while doing this. You can also move a toy or some food around the animal's head to evaluate the
range of movement. Open the mouth to identify pain from the temporomandibular joints or tympanic bulla area, and then palpate
the thoracic and lumbar spine by using moderate pressure with one finger on each side of the spine. For the lower back and
lumbosacral area, elevating the tail and extending the hips (avoid the latter in dogs with known painful hips or hip dysplasia)
can help identify pain in addition to applying digital pressure to the lumbosacral area. Dorsal pressure through rectal palpation
can be useful in identifying lumbosacral pain.5,6
Before making your final assessment of the lesion's location, make sure to note any other abnormalities in the animal, such
as generalized tremors or seizures.
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