Differentiating Orthopedic and Neurologic Disease
World Small Animal Veterinary Association World Congress Proceedings, 2015
A. Fauber1, DVM, MS, DACVS, DACVIM (Neurology)
1College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA


Patients with orthopedic disease can often have the same history or presenting complaint as patients with neurologic disease. What is the best way to tell these patients apart? This lecture will focus on a video review of cases of neurologic and orthopedic disease to help veterinarians hone their skills of observation to differentiate these tricky cases.

General Physical Examination

Don't forget this very important step! Measurement of a patient's temperature, lung auscultation, palpation for subcutaneous masses, and heart auscultation with evaluation of pulses simultaneously are very important.

Orthopedic Examination

When performing an orthopedic examination, it is important to develop a systematic approach to your exam. If you follow that same systematic approach each time you do the exam, you will not be left wondering if you forgot to thoroughly examine a long bone or joint. For dogs, saving the most significantly affected limb for the end of the exam is typically the best strategy. For many cats, a complete orthopedic exam is not well tolerated, so starting the examination with the most affected limb is often advised.

Observation of Patient While Moving

For dogs, walk and trot the dog up and down the hallway. It is easier to evaluate the symmetry of the movement of the front limbs and the hindlimbs if you keep the dog walking at a consistent speed and try to prevent him from stopping to look around or sniff the floor. Note if the patient is bobbing his head when he walks, places a limb further underneath or further out from the body when compared to the opposite side, and whether there is a natural fluidity to the movement or a short, stilted gait.

Observation of Patient While Standing

Allow the animal to stand stationary and undisturbed. Look for signs that the patient is placing the affected limb out to the side to avoid weight-bearing or is shifting weight significantly to the front limbs or the hind limbs. Often patients with hind limb lameness will intermittently pick the affected limb up off the ground while standing.

Palpation of the Limbs When Standing

It is often easier to examine patients for signs of joint effusion and swelling when they are standing and bearing weight on the limbs. Starting at the top of each limb, palpate both of the front limbs or the hind limbs at the same time and work your way down the legs. Pay close attention to any differences between muscle mass, tendon distinction, and joint size.

Palpation of the Limbs When in Lateral Recumbency

Always start the examination at the paw and work proximally on the limb. Palpate each joint by flexing and extending the joint through a complete range of motion. Specific manipulation of each joint can be performed to assess for collateral ligament stability, musculotendinous health, cruciate ligament integrity, and instability or laxity. Musculotendinous disease can masquerade as bone or joint disease, so manipulations of the limb to stretch the muscle-tendon unit are recommended. Palpate each long bone starting distally and slowly moving proximally. Feel for bone abnormalities and observe the patient for signs of pain.

Neurologic Examination

The systematic approach to the neurological examination is equally important. Assessment for hyperaesthesia or the presence of pain sensation should be saved to the end of the exam.

Observation of the Patient While Moving

The exam should include observation of the patient's gait. Ideally this is done on a non-slick surface and at varying speeds (walking and trotting). Observations about orthopedic disease and neurologic disease can occur at the same time. Close attention should be paid to position of the head and neck, occurrence of stumbling, difficulty initiating steps, and evidence of dysmetria.

Evaluating the Patient While Standing

While supporting the patient's weight, gently turn over one paw and slowly lower the patient's weight back on to the limb. Observe if the patient quickly replaces the paw back to the normal standing position. In order to properly assess this, the animal must be weight-bearing on the limb you are testing. This can be difficult in patients with orthopedic disease who are reluctant to bear weight on the limb. Hemiwalking and hopping can be performed at this time as well.

Cranial Nerve Examination

On routine examination, menace response, pupillary light reflex, oculocephalic reflex, and pupillary symmetry can be examined. If abnormalities are found or a neurologic disease is suspected, a more complete cranial nerve examination can be performed.

Segmental reflex evaluation


How to perform

Nerve(s) tested

Spinal cord segments

Extensor carpi radialis reflex

Palpate the proximal antebrachium for the extensor carpi radialis muscle, using a pleximeter, tap the ECR muscle belly, the carpus should extend.

Radial nerve


Biceps brachii reflex

Place your finger over the biceps tendon to ensure that the tendon is taut, using the flat end of the pleximeter, strike your finger, a contraction of the biceps muscle is seen and slight flexion of the elbow.

Musculocutaneous nerve


Forelimb withdrawal reflex

Pinch the webbing of the paw or the toe with your fingers, the carpus, elbow, and shoulder should flex.

Brachial plexus


Patella reflex

Place the stifle in slight flexion, using the broad end of the pleximeter strike the patellar tendon in the relaxed limb, the stifle should extend.

Femoral nerve


Cranial tibial reflex

Identify the cranial tibial muscle. Strike the muscle with the pleximeter.

Peroneal nerve


Hindlimb withdrawal reflex

Pinch the webbing of the paw or the toe with your fingers, the tarsus, stifle, and hip should flex.

Sciatic nerve


Perineal reflex

Using hemostats, gently pinch the skin around the anus, the anal sphincter should tighten, and the tail should flex.

Pudendal nerve


Cutaneous trunci reflex

Pinch the skin on the dorsum from wings of the ilium cranial to shoulders, the skin of the back should twitch bilaterally.

Lateral thoracic nerve


As you watch the videos in lecture ask yourself:

1.  Is the gait abnormal? If so, what is abnormal about the gait?

2.  Does this patient have neurologic or orthopedic abnormalities, or both? Why do I think that?

3.  How could I investigate this further?


References are available upon request.


Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

A. Fauber, DVM, MS, DACVS, DACVIM (Neurology)
College of Veterinary Medicine
Purdue University
West Lafayette, IN, USA

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