An Emerging Neurological Problem
in American Staffordshire Terriers :
Spinocerebellar or Hereditary Ataxia
(the following article has been edited and was originally written by Dr.
Natasha Olby)
The Problem
As with all pure bred dogs, American Staffordshire terriers exhibit some
health problems that are most likely the result of genetic defects. Recently,
the Staffordshire Terrier Club of America's health committee has noticed
that there are increasing numbers of dogs developing a drunken, staggering
gait and balance problems as they get older. This is a particularly serious
disease, as dogs do not exhibit signs until well into adulthood, after
they have been bred. Current research indicates that this is most likely
a genetic disorder.
The Symptoms
This disease affects a particular part of the brain called the cerebellum.
The cerebellum is closely associated with the vestibular system and together
these parts of the brain control coordination of movements. There are
many different diseases that can affect these areas of the brain and therefore
produce similar signs. Infection of the middle ear, trauma, viral infections,
tumors, autoimmune disorders and bacterial disease can also cause vestibular
and cerebellar signs. However, the order and rate in which signs develop
in dogs with this particular syndrome are characteristic of the disease.
Both male and female dogs are affected and signs may start from 2 - 5
years of age.
Initially, the signs are very subtle and include clumsiness and an occasional
sway of the body when making sudden movements. Agility dogs, for example,
may develop problems with a particular obstacle that they could previously
negotiate without difficulty. Dogs may trip and fall when negotiating
steps or moving quickly. As the disease progresses, the clumsiness becomes
more pronounced: dogs may fall over when they shake their head and often
have an obvious body sway when they move their head quickly. Male dogs
may lose their balance while lifting their legs to urinate. When moving
in a controlled fashion in a straight line they may still look normal,
but when turning corners, chasing balls, and rushing for their food, the
mistakes become obvious.
If the dog's eyes are watched carefully, it is noticed that sudden movements
of the head cause rapid flicking of the eyes (nystagmus), either from
side to side, round in circles or vertically. Rolling the dog onto its
back is the most reliable way of eliciting these eye movements and they
usually last from a few seconds to about one minute.
Other early signs of the disease may include sudden episodes of collapse,
with stiffening of all 4 legs, the neck and the body that last for a few
seconds. With time, the dogs have more and more difficulty walking because
of lack of coordination of their legs rather than weakness. The AmStaf
may also lose weight as the dog has balance difficulties reaching his
food bowl.
Please remember that we are very early in our data collection process.
The age of onset, symptoms, and progression varies from dog to dog. The
above descriptions are general signs of hereditary ataxia. Your dog does
not have to have every characteristic listed in order to be considered
affected. The one similarity that all the dogs have shared thus far has
been balance problems.
The Prognosis
The progression of the disease varies from dog to dog. For many AmStafs,
the signs develop slowly. The STCA health committee considers hereditary
ataxia a "deadly" disease since most AmStafs cannot live out
a normal lifespan and must be humanely euthanized. Most are not able to
function past the age of 7 or 8. One note: if anesthesia is performed
for some reason (e.g. a routine dental), it may accelerate deterioration.
We have witnessed dogs with minimal signs waking up from anesthesia extremely
unbalanced with obvious nystagmus. These signs improve somewhat in the
days after anesthesia, but the dog does not recover to the level it was
at prior to anesthesia.
The Diagnosis
If you have an AmStaf exhibiting any neurologic signs, (even those considered
to be the result of an ear infection or vascular event like a "stroke")
it is HIGHLY recommended that you seek the advice of a veterinary neurologist.
If you need assistance or advice, please contact Dr. Natasha Olby and
her research team at the below numbers. A complete neurologic workup is
most helpful in ruling out the many other types of disease processes that
can produce the same symptoms. Tests that may include a complete blood
cell count, a biochemistry panel, a computed tomography (CT) scan or magnetic
resonance imaging (MRI) to evaluate the brain and middle ears for evidence
of a mass (such as a brain tumor) or infection in the middle ears, and
cerebrospinal fluid analysis (spinal tap) to rule out encephalitis. In
dogs with this syndrome, all test results are normal. Post mortem examination
by a pathologist is one of the most helpful diagnostic tools we have.
Data gathering is critical to halting the spread of this terrible disease.
The Research
Dr. Natasha Olby has evaluated several of these dogs at North Carolina
State University veterinary teaching hospital and she is working to identify
the genetic defect causing this problem. Our aim is to develop a test
for the disease to identify affected dogs prior to breeding them. Similar
syndromes occur in people and the genetic defects that cause many of them
have been identified. We are therefore starting our research by looking
for the same genetic defects described in humans.
We are interested in information from dogs who are currently exhibiting
the problem as well as dogs thought to have died from this disorder (or
a similarly progressive neurologic disease). For those of you who have
had dogs die some time ago, your information is still very valuable to
us. If you suspect that your dog has this problem, please contact Dr.
Olby's research team by telephone: 919-513-6327 (ask to speak to Jeanne
Burr) or by e mail (jeanne_burr@ncsu.edu).
They will need a description of your dog's signs, with a videotape if
at all possible. They will be able to tell you where the nearest veterinary
neurologist is located if they feel that your dog would benefit from a
full diagnostic work-up. If Dr. Olby suspects that your dog has this disease,
we would appreciate your help in solving the problem. All information
is strictly confidential and will be maintained by Dr. Olby and her team.
No one else (including the health committee) will have access to raw data.
We are trying to determine how this disease is inherited and the researchers
may ask you for a copy of your dog's pedigree: this information will be
kept completely confidential at the vet school. Blood samples may also
be requested from your vet and would enable Dr. Olby to perform genetic
analysis. These will be kept solely for the purposes of this research
project.
Investigator: Natasha Olby Vet. M.B., Ph.D., Diplomate ACVIM (Neurology)
Research Assistant: Jeanne Burr 919-513-6327
If you would like to help but you do not have an affected dog, you can
contribute directly to the cause via donations. Checks can be sent directly
to the :
AKC Donation Founds
251 W. Garfield Rd. Suite 106
Aurora
Ohio 44202-8856
U.S.A
Please include on the memo portion of the check "American
Staffordshire Terrier Donor Advised Fund". Donations are tax deductible
and can only be used in health research for the AmStaf. Please do not
contribute directly to the health committee.
The Recommendations
Evidence indicates that this disease is on the rise, and that it may be
present in Europe as well. We are working with our counterparts there
to gather more information. Until genetic testing is available, we can
only make recommendations for breeders to avoid spreading this disease.
Because ataxia is a late onset disease, do not breed young stock. Do not
breed ANY dog with neurologic symptoms (this includes those thought to
be caused by ear infections and strokes) unless it has been definitively
diagnosed to have a non-hereditary disease process by a neurologist. If
you suspect a problem with your dog, please participate in our research
project. It is completely confidential, and it is the only way we can
battle this terrible problem.
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one(s).
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