called Enostosis, or Pano for short
Pains for Dogs?
We have all heard the term growing pains and when this term is
applied to dogs, more often than not it is referring to panosteitis.
Growing pains in children involve leg pains of unclear origin that
generally resolve when the child enters teen years. Panosteitis in dogs
is a specific painful bone condition involving the long leg bones of
large breed dogs generally between ages 5 and 18 months. The condition
can be quite painful during its flare-ups but ultimately resolves
permanently when the pup outgrows it. As in humans with growing pains,
the cause of panosteitis is not clear cut. Panosteitis is often referred
to as growing pains because of the similarity to the human malady.
of panosteitis is relatively straight forward. The clinical picture of
an adolescent large breed dog with long bone lameness is suggestive of
numerous developmental bone diseases, such as hypertrophic
osteodystrophy, osteochondrosis dissecans, panosteitis etc. In
panosteitis, there is a slight predisposition of males over females.
While larger breeds are more commonly affected, any dog could
potentially develop this condition. The lameness can shift from one leg
to another and can be accompanied by fever. Painful episodes last 1 to 3
weeks typically but recur, often changing legs, until the puppy outgrows
In panosteitis, characteristic cloudiness in the bone marrow cavities is
visible on radiographs. If there is any doubt about whether these
lesions are really there, radiographs can be repeated in a couple of
weeks and the lesions will likely be more prominent.
is aimed at relieving the pain until the puppy outgrows the problem.
What Causes Panosteitis?
What is actually happening inside a bone with panosteitis is
complicated. A bone's marrow cavity contains two types of marrow:
hemopoietic marrow that produces blood cells and fatty marrow, which is
basically just fat. In panosteitis the fatty marrow is replaced with
fibrous tissue. The fibrous tissue is then replaced by a type of bone
called woven bone. On a radiographic image, woven bone is represented by
marrow cavity can be nearly obliterated by encroaching woven bone.
Eventually, the normal cells involved in bone remodeling finally take
over, building new bone where it should be and dissolving bone where it
should not be. Ultimately, the bone tissue is re-structured back to
causes all this to happen in the first place is unclear and open to
speculation. There is some evidence of an infectious cause: a normal dog
will develop panosteitis if it receives a bone inoculation of marrow
from an affected dog. Furthermore, some dogs develop a fever and high
white blood cell count along with their bone issues, indicating an
infectious cause. Bacteria have not been cultured from panosteitis
lesions but it has been surmised that a virus is involved. Still,
despite extensive study, an infectious agent has not been isolated.
theory is that the recent trend in high-protein dog foods is to blame.
The idea here is that protein accumulation in the bone marrow leads to
swelling inside the bone. Because the bone is a rigid structure and
cannot expand, pressure is exerted on the blood vessels leading to
tissue death, inflammation and the panosteitis phenomenon. This is still
just a theory.
Since there is a breed predisposition for panosteitis (German shepherd
dogs, Golden retrievers, Basset hounds, Doberman pinschers, and Labrador
retrievers), this implies a genetic basis. It has often been noted that
most of the breeds predisposed to panosteitis are also the breeds
predisposed to the genetic blood clotting disorder called Von
Willebrand’s Disease. It has been suggested that dogs with
panosteitis be screened for Von Willebrand’s Disease as part of their
The cause of panosteitis is still a matter of theory and investigation.
No one really knows what causes it.
mentioned, the only treatment is pain relief until the dog outgrows the
condition. For most dogs this means one of the anti-inflammatory pain
relievers such as Rimadyl,
or Previcox. If this is inadequate, combinations of adjunctive therapy
and pain relievers can be used. The ultimate cure, however, is time.
consult with your Veterinarian before giving any type of medication or
the for the health of your dog.
4/25/2011 10:13:00 AM
Date Reviewed/Revised: 04/25/2011
consult with your Veterinarian for treatment or before treating your dog
with any medication