F

or all terrestrial animals, essential information about
their environment is transmitted by their feet. Think of
your own experiences. Did you like to go barefoot when

you were a kid? Remember the feeling of lush green lawn
underfoot, of hot sidewalk, of ouchy pebbles or a trail in the
woods? Your feet told your brain the texture, temperature
and firmness of the ground beneath you in an instant. Now
think of wearing unfamiliar shoes, maybe even high heels if
you are unaccustomed to them. What if you want to dance,
or run for your life? How confident would you be? Now
imagine having a pebble in your shoe. All you can think
about is how quickly can you sit down, take that shoe off
and get rid of it.

Ground surface. 

Our brains and those of our highly in-

telligent companion animals are hard-wired to interpret crit-
ical information through the soles of our feet and the
sensory nerves in our leg joints, tendons and muscles. They
tell us where the ground is, how hard is it and whether it
supports our bodies. One of the mechanisms we use is a skin
surface “map” on the bottom of our feet (or paws) that 
registers body weight and sudden changes in weight 

bearing. For instance, if your dog is running in a field 
and puts a foot into a hole, perceiving changes in the 
angle of the leg and pressure on the foot will trigger a fast
withdrawal of that leg and shift of body weight, preventing
a serious accident.

Unfortunately, our modern man-made environments

tend to alter the sensitivity of this feedback loop. Our dogs
spend much of their time on slippery floors, abrasive 
concrete or pile carpet — all pretty unnatural surfaces! 
But dogs, as domestic animals, are highly adaptable. Most
dogs with an intact nervous system can program a neural 
response to deal with these environmental changes. 

But when a dog has neurologic challenges, like advanced

age, hind-end weakness or spinal disease, we have to 
carefully consider whether the information they are getting
from their feet is helping or hindering their locomotion.
Even in a healthy dog, the “domesticated lifestyle” of 
artificial surfaces and limited exercise can interfere with
their foot-brain connection.

When did you last get a pedicure?

One of the most

common foot issues among canine companions is long 
toenails. In wild canids, miles traveled daily over rough 
surfaces to “make a living” result in appropriately short
nails. What is an appropriately short nail? One that does not
touch the ground when standing on a firm level surface but
will give useful traction when climbing a hill or digging.

So the only time a normal dog’s nail should contact 

the ground is when it is climbing a hill. In a dog with 
overgrown nails, the neurologic signal from a long toenail
contacting the ground is interpreted by the brain as an 
inclined ground surface. This abnormal compensatory 
posture results in too much weight carried by the hind legs,
thus overloading those joints. Many animals who seem to
be lame or weak behind can be helped enormously with just
an effective nail trim that changes this posture. 

Show dogs are groomed and clipped regularly for 

aesthetic reasons, but reap enormous musculoskeletal 
benefits from this beauty regime.          continued on page 64

62

www.pbgv.org

Summer 2014   

I Saber Tails

I  PBGV Health    

by Karen Gellman, DVM, PhD and  Judith Shoemaker, DVM
Introduction by Laura Liscum

“Click, click, click” is the sound I hear when I open the treat
jar in the kitchen. Soon there are big hopeful PBGV eyes
looking up at me. I hear the same “click, click, click” as we
walk around the block on the pavement. My PBGV’s nails
are trimmed every five weeks by her groomer, and I've 
always thought that was enough. However, Dr. Judith 
Shoemaker, the Health Seminar speaker at the PBGVCA 
National Specialty, has convinced me otherwise. Dr. 
Shoemaker described how nails that are long enough to
“click” can alter the posture and gait of a dog, leading to
orthopedic problems. This article by Karen Gellman, DVM,
PhD, and Judith Shoemaker, DVM, on the importance of
proper nail clipping is reprinted with permission of the
American Kennel Club Canine Health Foundation.

Feet

on the 

Ground