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When you buy a beardie puppy you want that puppy to be with you -
happy and healthy - for as long as possible, because as we know
dogs' lives are all too short. The most important things for most
puppy buyers are health and temperament. If you want to show and
perhaps even breed your puppy at a future date then his conformation
and type become very important too. If you are a beardie breeder,
then producing healthy puppies of good temperament should be a
primary goal. You are looking to improve the breed so conformation
of sire and dam, pedigree and a number of other factors come into
consideration. The most perfect puppy conformationally is not going
to improve the breed however if he becomes crippled with arthritis
or dies at an early age. As guardians of our breed, our beardies
must not only look like beardies, act like beardies and have that
quintessential beardiness about them, we must protect the breed from
introducing health problems which could doom our puppies to lives of
pain and misery or early death, or which could be seeding a problem
for generations to come. With this in mind, breeders and buyers have
common goals. In this column I'll be discussing the tests breeders
can run on the potential sire and dam of their litters to ensure
that the puppies they produce will have the best chance for living
long and pain-free lives and passing these traits on to future
generations. Fortunately ours is a fairly healthy breed in
comparison to many others, it behoves us all to keep it that way.
Although the incidence is very low in this country - albeit more
common in rural areas and the south - and it is a disease with no
breed preferences, it is important to ensure that sire and dam are
both free of brucellosis. This is a bacterial disease
that results in abortion and infertility in females and ultimately
testicular atrophy and sterility in dogs. Other parts of the dog are
very rarely affected, and unless the dog is tested the disease won't
be discovered until it has wrought devastating damage to a breeding
program. To prevent this all bitches should be tested before they
come into estrus (heat) if it is planned to breed them. Dogs should
be tested at least annually or before breeding if they are used
infrequently. New dogs should be tested on purchase and again a
month later to prevent introducing the disease into a kennel. Be
sure to allow adequate time for testing. Frequent false positives in
the initially used test, may require a second or third type of test
be done to ensure the dog doesn't have the disease. There is no
vaccine for brucellosis and no proven cure. If a dog has tested
positive on all three tests it should be removed from the kennel and
spayed or neutered. There is some evidence that prolonged use of the
antibiotics minocycline or doxycycline may clear the infection from
a dog, but this is an expensive and lengthy proposition and nobody
would advocate re-introducing such a dog into a sensible breeding
program, no matter what its virtues.
Canine hip dysplasia (HD) has been reported to
have an incidence of between 9 and 10% in beardies. How accurate
that figure is we do not know. Certainly not all beardies are being
tested and often times owners will choose not to submit X-rays for
evaluation if their vets, or they themselves, believe that the dog
will be deemed dysplastic by the veterinary radiologists who
evaluate hips for the various registries. HD is the result of a poor
match between the head of the femur (thigh bone) and the acetabulum
(hip socket). This mismatch leads to deformity of the femoral head
and acetabulum as well as damage to the articular cartilage,
resulting in micro fractures and degenerative joint disease (DJD).
The degree of laxity – looseness – of the joint determines the
severity of the disease and the amount of DJD the joint ultimately
sustains. HD is a polygenic disease. There is no evidence that
environmental factors such as diet, weight, and amount and type of
exercise can cause HD, although they can certainly exacerbate it in
predisposed dogs.
Particularly in cases where the dog is mildly dysplastic there
may be no clinical signs, particularly in young dogs of breeding
age. Severely affected dogs are often reluctant to move –
especially up stairs or jumping - and less active than normal.
Lameness may be either intermittent or constant, and they may bunny
hop, sway or be base narrow behind. As DJD worsens thigh muscles
atrophy and increasing debility and arthritis become more prevalent.
The most common method for hip evaluation involves taking
radiographs of the hips with the dog lying on its back with the hind
legs parallel and extended. The largest registry performing this
kind of evaluation is the Orthopedic Foundation for Animals (OFA www.offa.org).
OFA has been a closed registry, in other words only dogs deemed
"normal" were listed. As of July 2000 owners will have the
option of deciding before they submit the X-rays whether to make the
findings "open" in which case even if the dog is deemed
borderline or dysplastic, the results will be reported in the
registry. Because HD is a developmental disease, all dogs are born
with apparently normal hips. As the dog ages however, signs of
dysplasia will begin to appear. While OFA reports that hip
evaluation is approximately 90% accurate at 4 or 5 months old when
compared to follow up radiographs at 24 months, the registry will
not assign a permanent OFA number to dogs less than 24 months old.
When OFA receives the X-ray it is assigned randomly to 3
board-certified veterinary radiologists. The rating is based on a
consensus of their opinions. If they disagree significantly then
further veterinarians may be asked for an opinion – this rarely
happens. Hips are classified as "normal" for which there
are three categories – excellent, good or fair. This information
together with the age at which the dog was evaluated, its sex, breed
and whether or not it was permanently identified (tattoo, chip or
DNA) appears in his OFA number. Dogs may also be deemed dysplastic
in three categories – mild, moderate and severe. If the
veterinarians are in doubt the dog will be termed borderline, and
reassessment in 6 to 8 months is recommended. OFA advises that
because hormonal effects may cause some bitches to show subluxation
they should not be radiographed within 4 weeks of the beginning or
end of their heat cycle, or within 4 weeks of weaning puppies.
Preliminary OFA evaluation can be performed for dogs between 4 and
24 months of age. A single board certified veterinary radiologist
evaluates the X-ray. Further X-rays must be submitted at 24 months
or older for permanent registration. OFA stresses that it is not
only important to breed dogs with "normal" hips, but they
should have an ancestry of normal hips and come from litters with
low or zero incidence of hip dysplasia.
In 1983, PennHIP was introduced to address a number of
shortcomings in the traditional method of hip evaluation. The latter
may give a false impression of joint tightness although it is good
at detecting existing DJD. For this reason the results are not
deemed reliable until dogs are 24 months or older. For PennHIP
evaluation a second "distraction" X-ray is taken of each
dogs hips. This enables the evaluator to measure the degree of
laxity of the femoral head in the acetabulum (distraction index -
DI). A third compression view is also recommended. The advantage of
PennHIP is that it enables accurate hip evaluation by 6 months of
age (or even 4 months although results are slightly less good.) It
also seems that joint laxity is more clearly heritable than DJD,
which can be affected by environment, and may be a better predictor
of hip health, particularly in dogs where extensive information
about other family members is lacking. However, there are
disadvantages. First the three radiographic views, which have to be
taken under heavy sedation or general anesthesia, add considerably
to the evaluation cost. More importantly, it seems that the
acceptable degree of laxity is somewhat dependent upon breed. More
heavily muscled breeds being able to sustain greater laxity. Too few
beardies have been evaluated by PennHIP to make clear
recommendations at this time, although dogs with DIs of < 0.3 in
each hip are preferred and dogs with DIs > 0.7 are at high risk
of developing dysplasia.
Another orthopedic condition that has been reported in beardies
is elbow dysplasia. Actually, this is a blanket term covering
at least three different developmental aberrations or a combination
thereof. By far the most common is fragmented coronoid process (FCP)
with or without osteochondritis dissecans (OCD) or condyle erosion
(>90%) while < 10% involve ununited anconeal process (UAP).
(The anconeal process is a bump near the upper end of the ulna –
the thinner of the two bones in the forearm. It fits into a notch on
the humerus – upper arm bone. There are two coronoid processes
slightly lower down the ulna into which the head of the radius –
the thicker of the forearm bones – nests. The medial one is more
likely to be affected. The condyle is a catchall name for the big
knob at the lower end of the humerus. OCD describes a condition
where flaps of thickened cartilage separate partially or completely
from the layer inside the joint, causing irritation and
inflammation.) We do not know how prevalent this problem is in
beardies, we do know however, that while elbow dysplasia is more
common than HD, it is less likely to be diagnosed. At this time
relatively few beardie breeders have been including elbow X-rays as
part of their pre-breeding testing and it is probably similarly
under diagnosed in the breed. The elbow is the most complicated
joint in the body and as such liable to more problems. As with HD,
dogs may not appear particularly painful while young, or onset can
be sufficiently slow as to be deemed a normal part of aging. Dogs
rarely complain about chronic pain, which is why owners are often
unaware that they are suffering from either hip or elbow dysplasia.
Pain is caused by fluid build up in the joint and the presence of
bone fragments. Eventually weight bearing may be compromised.
Healthy dogs bear 60% of their weight on their front legs, with
elbow dysplasia this may drop to 40 to 50%. The elbow may appear
fused in extreme cases. Screening X-rays for elbow dysplasia require
that the joint be radiographed in extreme flexion. OFA also has a
registry for elbows. Animals must be 24 months or older. As with HD,
there will be the option to choose to be part of the open registry
after July. While there is only one category for normal elbows at
this time, abnormal elbows may be reported as Grade I- minimal bone
change on the anconeal process; Grade II – additional subchondral
bone changes and or osteophytes (remodeling of bone in the joint);
Grade III – well developed DJD.
The eyes also do not seem to be getting the attention they
probably deserve. There seem to be an increasing number of beardies
going blind. Like the bones, the eyes tend to change most
dramatically during early to middle years when a dog is being used
for reproduction. For this reason, the Canine Eye Registration
Foundation (CERF), located at Purdue University’s School of
Veterinary Medicine, recommends annual testing of dogs. As with OFA
data, your dog’s CERF status will appear on AKC registration
forms, provided your dog has been permanently identified (tattoo,
chip or DNA). At this time CERF is a closed registry. Only dogs
deemed free of heritable eye disease can be registered. However, the
examining veterinarian, who must be a board-certified diplomate of
the American College of Veterinary Ophthalmologists (ACVO) submits
data on all dogs which fail to test clear. This data is used for
research purposes. From 1991 to 1999 a mere 931 beardies were
examined. While an encouraging 761 (81.74%) tested clear a variety
of different types of cataracts (lesions of the lens) were reported.
Another common problem seen was persistent pupillary membranes (PPM
- remnants of embryonic blood vessels). This was found in more than
1 in 6 of the beardie eyes examined at the CERF clinic offered when
MBCC staged the 1998 BCCA specialty. Retinal atrophy and globe
(eyeball) problems were also reported. It should also be born in
mind that not all cases of PPM would be reported. Many
ophthalmologists do not examine the eye before dilating the pupil.
Because PPM are present on the iris, which retracts when the pupil
dilates, they will not be seen (or not as clearly) on post-dilation
examination. While PPM and cataracts have been deemed heritable in
many breeds, PPM is not a disqualifying fault at this time for
beardies. Given the reported incidence CERF may change their opinion
on that in the near future. In the meantime however, beardies with
PPM receive CERF registration. Whether or not an ophthalmologist
decides certain types of cataract are heritable or not is also
somewhat in the hands of the individual currently.
Probably autoimmune diseases – diseases in which the immune
system fails to recognize self and forms antibodies against a part
of its own body - are the most feared in the beardie community, but
at this time we do not have a predictive test for them. The most
common autoimmune disease in beardies and other dog breeds is hypothyroidism
– or immune mediated thyroiditis. This is not particularly
surprising, dogs that couldn’t reproduce due to insufficient
thyroid hormones have traditionally been bred after supplementation,
and we know this happened with beardies. What wasn’t known at the
time, however, was that hypothyroidism might also predispose an
animal to develop other autoimmune diseases. Recently, we have also
learned that hypothyroidism is often manifested in its earliest
stages in behavioural problems – aggression, hyperactivity,
fearfulness and obsessive behaviours. All of these have been seen in
beardies. Testing breeding stock for hypothyroidism is clearly
prudent. However, the most common thyroid test (total T4) done in
veterinary medicine is rarely positive until 2/3rds of thyroid
function has been lost. It is recommended that the whole thyroid
function be examined through a thyroid profile. Many labs offer a
6-analyte-thyroid profile (total and free thyroxine (T4) and
triiodothyronine (T3) as well as autoantibodies to T3 and T4.) For
breeding stock it is optimal that the first four of these be in the
upper 50% of lab normal values, and for animals under 18 months the
upper 75%. In dogs over 8, thyroid levels may drop below the
midpoint as metabolism begins to slow. OFA also offers a thyroid
panel measuring free T4 by equilibrium dialysis, canine TSH levels
and thyroglobulin autoantibodies. It should be noted that much
controversy exists as to which testing method is preferable.
Different labs use different assays to measure the various analytes
and these are of variable accuracy. Dogs should be tested once they
have passed puberty. Bitches should be tested during anestrus, the
period 12 weeks after the end of the previous heat to 12 weeks
before the onset of the next heat. It is recommended that both dogs
and bitches be retested annually. This allows comparisons for early
recognition of developing thyroid dysfunction. The earlier treatment
is initiated the fewer clinical problems associated with
hypothyroidism will be manifest. If a dog tests low it should not
necessarily be removed from the breeding program. Illness may drop
circulating thyroid levels (sick euthyroid) as will various
stressors. However, it would be unwise to breed the dog until a
follow up panel showed that its hormonal levels had returned to
normal. At the same time, if a dog shows clinical signs of
hypothyroidism but the serum (blood) levels are normal it may have a
deficiency of the hormones at the tissue level. If the dog responds
to a 6 to 8 week trial of thyroxine replacement this is very likely
the case. Selenium deficiencies may manifest in this fashion.
While we are still waiting for a genetic test for Addison’s
disease, an annual complete blood count (CBC) and biochemical
profile may prove very helpful for early detection. In
Addison’s disease the body’s ability to balance sodium and
potassium levels is usually the most seriously compromised function,
and as a result nerve and muscle activity is impaired. The
biochemical profile gives baseline data on electrolyte levels
(including sodium and potassium) so any changes from one year to the
next are clearly seen. Important information on liver and kidney
function is also to be found. The CBC, as its name implies, gives
information on numbers of the various types of blood cells, allowing
anemia, thrombocytopenia and leukemia to be recognized. Signs of
infection and stress can be detected, too. Any slightly
"abnormal" normals for a particular dog will be seen from
year to year. (For example many beardies have a normal level of
eosinophils – a kind of white blood cell – that is slightly
higher than lab normal.) Early detection and treatment results in a
better prognosis for almost every condition.
Another blood test that is advisable is for von Willebrand’s
factor (vWF). Von Willebrand’s Disease (vWD) is a bleeding
disorder somewhat akin to hemophilia. VWF circulates in the blood
and helps platelets to stick together to form plugs when there is a
breach of the blood vessel wall. We know that beardies have a mild
form of the disease. As for many diseases we do not know the
prevalence in the breed. Often the disease is found during surgery,
and some beardies have bled to death during spay/neuter operations.
For many breeds VetGen has a DNA test. This is probably effective
for beardies too, but as yet insufficient beardies with vWD have
sent samples to the lab to prove this. For now, a blood test is
necessary to measure vWF levels. Like PennHIP there is a gray area
between known carrier and known clear. We can only suggest that dogs
in this range be bred to dogs that have significantly higher vWF
levels. The level of vWF in the offspring tends to average those of
the parents. A single popular sire with low vWF levels could be
disastrous, as it was for Dobermans, where 90% of dogs were carriers
for the disease before the problem was recognized.
OFA operates a couple of other registries that may be relevant
for beardies. It has been reported that beardies are at risk for a
cardiac condition called subaortic stenosis (SAS). SAS is a
narrowing of the aorta just below its exit from the heart. This
means that the heart has to work harder to pump blood out to the
body. In clinical cases a systolic ejection murmur should be
detectable. Echocardiographic (ultrasound of the heart) screening of
the heart may be advisable, especially in beardies with relatives
that have been diagnosed with SAS.
Patellar luxation – displacement of the
kneecap – is most common in toy and small dogs. We have little to
indicate that this is a significant problem in beardies.
At this time I would recommend that all dogs be tested for
brucellosis a few weeks before breeding, or annually/biannually for
stud dogs that are used fairly frequently. Hips and elbows should be
X-rayed at 2 years of age, or earlier if the dog is to be used
before it is 24 months old. CERF and thyroid preferably should be
repeated annually post puberty (for bitches these tests, as well as
X-rays and vWF test, should be done during anestrus.) I would also
strongly recommend annual CBC and biochemistry profile and a
post-pubertal vWF. In the future, as new and better tests become
available these recommendations will doubtless change. The canine
genome project approaches completion, and it is not inconceivable
that a DNA profile of our dogs will be all that’s needed to assess
a dog or bitch’s status as regards these and other inherited
diseases.
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