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GSDCA
- Veterinary Information - GSD Conditions, Disorders and Diseases - Published
Articles
GSD HEALTH AND VETERINARY
PUBLISHED ARTICLES
The German Shepherd
Dog Council of Australia has developed a number of schemes to combat conditions,
disorders and diseases that adversely affect the German Shepherd Dog as
a breed. Integral to that process, it has a Hereditary Diseases Subcommittee
to monitor, investigate and recommend remedial action on emerging disorders
that may affect breed development. Through these initiatives, the GSDCA
and its affiliate members have built up much knowledge and resources on
the veterinary aspects of many disorders/conditions. Also over the years,
many articles have been published in the GSDCA National Review Magazine
to inform GSD enthusiasts of topical veterinary and health matters.
If you wanted raw veterinary
data (definitions) or general published data, you may return to those streams of information by accessing the following
links :
This stream of information
has articles categorized under group headings to enable a systematic presentation
of data.
GSD HEALTH AND VETERINARY
PUBLISHED ARTICLES.
User note :
The articles have
been listed in a systematic approach, in order to group the various items
applicable to that system together.
How
to operate the
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Click on the required
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Only where there is
an active link (text with underline), ie "Hip Dysplasia (HD)", will
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GSD
CONDITIONS, DISORDERS AND DISEASES PUBLISHED ARTICLES
Index
and Links
DEFINITIONS
GSD
CONDITIONS, DISORDERS AND DISEASES PUBLISHED ARTICLES :
IMMUNOLOGICAL
General
Information
Ig
A Dysfunction
BONE
(and JOINT)
The
consequences of increasing weight and rapid growth
Hip
Dysplasia (HD) - What Price a Normal Hip
-
Elbow
Dysplasia (ED) - Elbow Dysplasia
-
Elbow
Dysplasia (ED) - Elbow
Dysplasia Control Scheme Report 2004 -
Panosteitis
Hypertropic
Osteodystrophy (HOD)
Cauda
Equina (Acquired Lumbosacral Stenosis)
Spondylitis
Diskospondylitis
Chondrodysplasia
- Chondrodysplasia in GSD's -
BLOOD
Haemophilia
A
Von
Willebrands
Blood
Tests - Refer to the HEALTH section below.
NEUROLOGICAL
Epilepsy
Tail
Chasing
Gun/Noise
Sensitivity - The Gun Test -
Degenerative
Myelopathy
HEART
Patent
Ductus Arteriosis (PDA)
Subvalvular
Aortic Stenosi (SAS)
Atrio-ventricular
Valve Dysplasia (AVD)
Persistent
Right Aortic Arch
Cardiomyopathy
INTESTINAL
Congenital
Mega-oesophagus
1.
Persistent Right Aortic Arch (PRAA)
2.
Mega-oesophagus
Mega-oesophagus
(Acquired)
Bloat
or Gastric Dilation and Volvulus (GDV) - Canine Bloat
-
LIVER
Portasystemic
Shunts
Idiopathic
Hepatic Fibrosis
GASTRO-INTESTINAL
- DIGESTIVE
Wheat
(Gluten) Allergies
Exocrine
Pancreatic Insufficiency
Pancreatic
Atrophy
Inflammatory
Bowel Disease
Eosinophilic
Enteritis
Chronic
Colitis (Lymphocytic-Plasmacytic)
Bacterial
Overgrowth
Malabsorption
Syndrome
Stress
Induced Diarrhea
HORMONAL
Pituitary
Dwarfism
MUSCULAR
Fibromyositis
of the Gracillus Muscle
SKIN
Collagen
Disorders of the Footpads
Deep
Staph Pyoderma (Furunculosis/Folliculitis/Cellulitis)
Acanthosis
Nigricans
Hypothyroid
- Thyroid Insufficiency -
Dyscoid
Lupus Erythematosis
Nasal
Keratitis
Pemphigus
SYSTEMIC
Aspergilosis
Systemic
Lupus Erythematosus
Sebhorrea
Deep
Staph Dermatitis
Calcinosis
Circumscripta
Perianal
Fistula (Anal Furunculosis)
EYES
Pannus
(Chronic Superficial Keratitis)
Plasmoma
EARS
Otitis
Externa
CANCERS
Haemangiosarcoma
Skin
Haemangiosarcoma or Malignant Haemangio-Endothelioma
Lymphosarcoma
Mammary
Gland Tumours - Refer to the GENERAL HEALTH section < vetinfo3.htm >.
FURTHER
REFERENCES AND LINKS
Text
References - Book Names -
Website
Links - www. addresses -
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DEFINITIONS
Inherited Disorders
- covers genetic disorders that have been inherited from one or both parents.
Many of these disorders do not have a well documented means of the exact
mode of inheritance. Hopefully over time this situation will improve. As
a loose rule of thumb, the more genes involved in an inherited condition,
the greater the effect of the environment (weight, diet), the greater the
range of symptoms seen and the harder it is to control and/or reduce the
incidence within the breed. Where there are exact tests that can positively
identify affected and carrier animals for a condition (be it a blood test
or DNA marker), then a condition can be readily removed from a breed within
2-3 generations if desired. In the polygenetic conditions, until reliable
DNA tests are developed, the policy of removing the worst affected animal
from breeding programs and promoting the soundest sires (with the best
progeny results) is the only slow but sure long term policy.
Congenital Disorders
- Means those present at birth. These conditions can be simple malfunctions
during development (can be secondary to environmental insults, chemicals
etc) while others can be inherited defects within that breed.
Acquired Disorders
- Are those that develop over time and are listed here as conditions seen
with some degree of frequency within the GSD breed.
Breed Predispositions
- These are conditions where the breed in question, the GSD, shows a higher
than average incidence of these diseases or conditions occurring than would
be expected in the general population.
Immunological Disorders
- Are defined by a diminished ability of the body to mount an effective
immune response to a perceived threat.
Cutaneous -
Of the skin.
Back
to Index
IMMUNOLOGICAL
General Information.
- Immunodeficiency disorders are defined by a diminished ability by
the body to mount an effective immune response to a perceived threat, eg.
infection. Primary immunodeficiency disease is caused by hereditable defects
in the immune system. Secondary immunodeficiency disease is a diminished
immune response acquired as a consequence of some other primary disease.
Primary immunodeficiencies involving the cell-mediated, humeral, complement
and phagocytic systems have all been described in veterinary literature.
Defects involving the humeral immune response are associated with a high
susceptibility to bacterial infection. Defects involving the cell-mediated
immune response are associated with a high susceptibility to viral, fungal
and protozoal infections. Defects in the phagocytic or complement system
are associated with disseminated infection.
Ig A dysfunction
- A primary Ig A deficiency has been described in the GSD and is probably
at the root cause of several GSD specific immunological disorders. Aspergilosis
in the GSD has been related directly to the Ig A deficiency and has an
almost 100% death rate. Other disorders including Staph folliculitis and
suppurative otits externa (ear infections) have also been directly linked
to Ig A deficiencies. Selective Ig A deficiency is the most common primary
immunodeficiency in man (approx. 1 in 600).
BONE
(and JOINT)
The consequences
of increasing weight and rapid growth.
Many of the joint diseases
that occur in the dog arise often as the consequence of rapid growth in
an increasingly heavy breed of dog (over time). Osteochondrosis (cartilage
degeneration and damage) and joint dysplasias have been studied in many
species, in particular in pigs.
In pigs, where the
animals were selected for increasingly heavy end weight and rapidity of
weight gain, the higher the incidence of symmetrical lesions in certain
sites in joints and many growth plates. Experimentally the incidence and
severity of osteochondrosis was directly related to rapid growth, ie. rate
of weight gain. When the diet was restricted and the animals were grown
at a low growth rate, the incidence of OCD was dramatically reduced (almost
to zero).
All dog studies in
this area have shown to support the concept that the high caloric intake
rather than the specific intake of protein, minerals or vitamins influences
the frequency and severity of osteochondrosis and HD. The causes of ED
while not as thoroughly studied, show similarities and probably similar
outcomes.
The common conclusion
from studies in dog is that excessive calcium, phosphorus and vitamin D
along with a high energy diet and rapid weight gain causing rapid growth,
are almost a sure fire recipe for pushing the parameters for normal structural
growth and joint soundness well beyond their normal limits, resulting in
joint disorders. The higher incidence of osteochondrosis in males versus
females is probably a direct reflection of this as males are often ¼
heavier than females at any one time, despite being born at a comparative
weight.
Equally this is not
to say that genetics does not pay an important part in the body’s structural
soundness, however excessive rates of weight gain and thus rapid growth
result in pushing the body’s parameters beyond which they can cope, particularly
if they were not the most structurally stable to start with, ie. excessive
rate of growth and weight will not create severe HD in itself; however,
it can make an existing problem considerably worse.
Rate of Weight Gain
- The causes of the development of hip dysplasia, as discussed below, are
from a combination of genetic and environmental factors. Rapid weight gain
and rate of growth through excessive nutritional intake can cause a disparity
of development of supporting tissues. Factors affecting cartilage integrity
(thickness and stability) and joint fluid composition, such as repeated
trauma from excessive looseness of the joint and /or bacterial infections,
can increase joint fluid production, thickening of the joint capsule, resulting
in both joint pain and reduction in joint stability. These factors contribute
to the development of joint looseness and subsequent subluxation, resulting
in early clinical signs and joint changes. Control of the rate of weight
gain, while it will not prevent hip dysplasia, it will allow a steady growth
pattern allowing the hip structure to mature in concert with the strength
of ligamentation in order to minimize excessive stress being placed on
the hip joint.
Conversely to osteochondrosis,
in breeds with a high incidence of HD, females generally have a higher
average than males; due it is thought to the influence of female hormones.
(a 4 point difference on average in the GSD).
HIP
DYSPLASIA
What Price a Normal Hip
Dr Karen Hedberg BVSc.
- 2002.
INTRODUCTION
The following article
is an attempt to cover the many and varied aspects of hip dysplasia; its
definition, the factors affecting the severity of the signs seen, the treatment
of HD as well as the control of HD by (a) various schemes and (b) the genetic
aspects. This somewhat rambling account is an attempt to show that the
control of HD by concerned breeders is both difficult and complex. Additionally,
the general public is being increasingly told that a “normal” hip is the
only one acceptable, and anything above that may require surgical intervention.
As both a breeder and
a veterinarian, we need to look at this problem from all angles and present
to the general public a more realistic view of the condition, not only
for ourselves, but for all breeds where clubs are trying to lower the severity
of the HD problem. As the general public is becoming far more litigious
in these matters it behoves us to present a rational approach with realistic
goals.
BREEDERS AIMS
When we are breeding
dogs, in addition to producing better show animals, we should also be trying
to breed as sound an animal as possible. This encompasses all of the following:-
physical, mental and genetic soundness as well as breed type (ie. it must
still resemble the breed!). All of these areas are of great importance,
some are weighted more heavily than others in different breeds. Over time
various areas come under heavier pressure, eg. With all the current adverse
publicity from dog attacks, heavier emphasis is being placed on temperament
issues (as it should). Compromises often have to be made when balancing
out the relative importance of different problems both within that animal
and the breed as a whole.
The bigger the number
of issues we attack at any one time, the slower the relative rate of improvement
of the breed as a whole. With breed improvement schemes, the larger the
number of genes involved in any one condition, again the slower the rate
of improvement as well as the larger the environmental effects.
Genetic problems that
result in a high incidence of blindness, crippling arthritis or vastly
shortened life span (eg. the storage diseases), where there is pain and
suffering on behalf of both the dog and the owner (be it monetary or emotional
stress), the greater the effort that should be made to decrease the incidence
of these problems.
The most important
point is to keep the problems a breed has within perspective. This means
that if there is a minor problem that does not affect the animal's soundness
either as a working animal or its quality and length of life, that it should
be kept in proportion relative to other problems within the breed.
BONE DISEASES IN
DOGS – the consequences of increasing weight and rapid growth.
General Discussion
Many of the joint diseases
that occur in the dog arise often as the consequence of rapid growth in
an increasingly heavy breed of dog (over time). Osteochondrosis (cartilage
degeneration and damage) and joint dysplasias have been studied in many
species, in particular in pigs.
In pigs, where the
animals were selected for increasingly heavy end weight and rapidity of
weight gain, the higher the incidence of symmetrical lesions in certain
sites in joints and many growth plates. Experimentally the incidence and
severity of osteochondrosis was directly related to rapid growth ie. rate
of weight gain. When the diet was restricted and the animals were grown
at a low growth rate, the incidence of OCD was dramatically reduced (almost
to zero).
All dog studies in
this area have shown to support the concept that the high caloric intake
rather than the specific intake of protein, minerals or vitamins influences
the frequency and severity of osteochondrosis and HD. The causes of ED
while not as thoroughly studied, show similarities and probably similar
outcomes.
The common conclusion
from studies in dog is that excessive calcium, phosphorus and vitamin D
along with a high energy diet and rapid weight gain causing rapid growth,
are almost a sure fire recipe for pushing the parameters for normal structural
growth and joint soundness well beyond their normal limits, resulting in
joint disorders. The higher incidence of osteochondrosis in males versus
females is probably a direct reflection of this as males are often ¼
heavier than females at any one time, despite being born at a comparative
weight.
Equally this is not
to say that genetics does not pay an important part in the body’s structural
soundness, however excessive rates of weight gain and thus rapid growth
result in pushing the body’s parameters beyond which they can cope, particularly
if they were not the most structurally stable to start with. ie. excessive
rate of growth and weight will not create severe HD in itself; however,
it can make an existing problem considerably worse.
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Maximum to
Minimum Mean Cumulative Weights
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Weight
(from 0 to 40
kilograms)
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Age
(from 0 to 20 months)
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Growth Chart
for German Shepherd Dogs
Average Proportional
Weight (Kilograms) Gain Curve for Normal Growth over Time (Months)
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Rate of Weight Gain
- The causes of the development of hip dysplasia, as discussed below, are
from a combination of genetic and environmental factors. Rapid weight gain
and rate of growth through excessive nutritional intake can cause a disparity
of development of supporting tissues. Factors affecting cartilage integrity
(thickness and stability) and joint fluid composition, such as repeated
trauma from excessive looseness of the joint and /or bacterial infections,
can increase joint fluid production, thickening of the joint capsule, resulting
in both joint pain and reduction in joint stability. These factors contribute
to the development of joint looseness and subsequent subluxation, resulting
in early clinical signs and joint changes. Control of the rate of weight
gain, while it will not prevent hip dysplasia, it will allow a steady growth
pattern allowing the hip structure to mature in concert with the strength
of ligamentation in order to minimize excessive stress being placed on
the hip joint.
Conversely to osteochondrosis,
in breeds with a high incidence of HD, females generally have a higher
average than males; due it is thought to the influence of female hormones.
(a 4 point difference on average in the GSD).
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Normal Hip
Structure and Nomenclature
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Stresses
on the Femoral Head
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HIP DYSPLASIA –
its definition and structural components.
This is a disease that
is very common throughout the dog breeds from Cocker Spaniels to Saint
Bernards. It is most commonly seen in the heavier bone to muscle ratio
breeds where the overall ligamentation is slightly loose. Hip dysplasia
is by definition an ill fitting hip. The hip is a ball and socket joint,
and the deeper the socket (ideally sufficiently deep to hold 2/3rds of
the head of the femur), the better fit of the femoral head and angle of
the neck and the tighter the ligaments, the better the hip.
The various components
that combine to give an unstable hip are combinations of the following
:-
shallow hip socket
(the acetabulum),
an ill fitting head
of the femur (head too small, neck too short and steep),
excessive looseness
of ligamentation.
Where the socket is
very shallow, the ligaments very loose and the femoral head either very
steep in the neck or the head very small, these combination of factors
lead to instability of the joint. Around the edges of the joint is attached
the joint capsule, which in turn is attached to the periosteum. When the
edges of the joint capsule are constantly being pulled, the periosteum
is lifted and new bone is laid down in an attempt to stabilize the joint.
Pain from hip dysplasia
is largely from wearing of the cartilagenous surface within the joint,
exposing pain fibres in subchondral bone. There are two groups of animals
affected :-
-
1. Young group - 4.5 -10
months (rapid growth phase) and
2. Older patients - with
chronic degenerative disease.
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Remodelling
of an Arthritic Hip
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Examination for
HD
Symptoms - Dogs
with HD have a history of intermittent hindquarter lameness, pain on rising,
poor hindquarter muscle development, narrow hindquarter action, reduced
arc of movement, reduced exercise tolerance. Examination under anaesethic
may show looseness while X rays will (if correctly positioned) give more
definitive view of anatomical details as well as arthritic changes and
the degree of joint looseness.
In should be remembered
younger, overweight dogs will be looser in ligamentation than older, fitter
individuals. Different anaesethic agents and depths of anaesthesia can
vary slightly the looseness of ligamentation seen. Positioning for X rays
for HD assessment – it is most important that of the pelvis should be level,
both from front to rear, and side to side. Too steep an angle of the pelvis
front to rear will give the appearance of a shallower joint. Twisted, crooked
pelvis side to side will have adverse effects on the hip tilted further
away from the X ray plate.
Heavier, larger and
looser ligamented breeds (and individuals) will exhibit the greatest arthritic
changes. Some breeds tolerate looseness better than others.
# Clinical signs
often do not correlate with radiographic changes. Some dogs with moderate
or even severe HD are asymptomatic.
Differential Diagnosis
- In both groups of affected dogs but particularly in the younger group,
the back should be assessed, especially when accompanied by generalized
soreness from excessively rapid growth. Soreness along the back, usually
obvious by arching along the middle (lumbar section), will affect the dog
in both rising and extension during movement and manipulation.
Rule outs: - In the
younger dog, lameness from other rapid growth associated conditions eg.
Panosteitis, OCD, HOD or other injury to joints in the hindquarters. In
the older dog, conditions such as cauda equina (neurological), acute or
chronic knee injuries, bone neoplasia need to be taken into account.
# HD rarely
if every presents as a sudden acute injury or onset.
Methods of Treatment
of HD
Treatment depends on
the age of the patient and the severity of the symptoms, physical and radiographic
findings and economics of the owner. Conservative and surgical options
should both be looked at. Many younger dogs (60%) spontaneously improve
with increasing age after conservative management and return to acceptable
clinical function (Barr, Denny, Gibbs 1987). The remainder requires further
medical or surgical treatment at some time in their life.
Surgical intervention
is indicated where conservative treatment is not effective, where athletic
performance is desired, or in young patients where owners wish to slow
the progression of degenerative joint disease and enhance the probability
of good long term limb function.(Small Animal Surgery 1997).
Medical Management
1. The younger patient
– rest, correction of diet and weight if needed, use of drugs such as cartrophen
to improve circulation to, and repair of cartilage, use of other anti-inflammatory
drugs. Rest and recuperation for as short as 2-3 weeks can make remarkable
improvements.
2. The older patient
– again weight should be considered as too heavy in condition will acerbate
wear all the joints, not just the hips. Again use of the same drugs as
above can give remarkable results. Rest with severe cases is always advised.
Non steroidal drugs
include Aspirin, PBZ (phenylbutazone), Rimadyl*, Metacam*, Cu Algesic*.
If dogs in either
group fail to respond to appropriate treatment, dietary changes and rest,
then surgical intervention may be necessary.
Surgical Intervention
1. Pectinomyotomy
– this is the mildest (also cheapest and quickest) way to get some relief
in the HD patient. This was used quite frequently in the past where there
were fewer options available. This muscle cutting operation transects the
pectinius muscle, a muscle that runs high on the inside of the thigh and
pulls the leg medially. Cutting this muscle relieves tension on the joint
capsule and eases movement by reducing medial pull of the limb. This can
be very useful in the younger patient, particularly where funds do not
permit the more radical operations. Can get good pain reduction, and does
not interfere with any other surgical option at a later date.
2, Triple Pelvic
Osteotomy – this is ideally done in dogs before they reach 9 months
of age, where the pelvis has not yet finished growing. This is done
to axially rotate and lateralize the acetabulum in order to increase the
dorsal coverage to the femoral head. This operation is not suitable where
there is insufficient depth of acetabulum to hold the femoral head. The
results are best where there is minimal degenerative change. Costs
- Generally both hips are done at once, cost is around $6000.
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Triple Pelvic
Osteotomy
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Total Hip
Replacement
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3. Total Hip Replacement
– is the replacement of a degenerative hip joint with a prosethetic acetabular
cup and a femoral head/neck component. This is used on the older patient
where conservative treatment is not effective. The success rate is good
to excellent with an orthopaedic specialist. This is usually not done much
on breeds or individuals that weight less than 20 kg (very hard to get
small enough prosthetics at this time). Costs - Cost per hip is
$3000 and up.
4. Femoral Head
and Neck Excision – limits bony contact between the acetabulum and
the femur and a fibrous joint is formed. This is a type of operation routinely
used with dislocations of the hip from trauma, in the case of HD dogs it
is used where conservative treatment has failed and there are financial
constraints against a total hip replacement. The results are no where near
as good as with (3), as there are fibrous changes and restrictions of movement,
but this is largely seen as a salvage procedure. However, many dogs do
very well and have improved function. ( # Once this operation has been
done, other surgical options are virtually nil.)
Discussion
Given the very high
percent of younger dogs that respond to rest, conservative treatment and
weight/dietary management (60%), ideally the first route of treatment should
be conservative, medical management. Many breeds are quite loose in their
ligamentation when young and if weight factors are above breed norms for
that age and sex, then conservative treatment with calorie limitation should
be tried.
Unless there are substantial
abnormalities present, ie. very shallow sockets, excessive luxation of
the joint with arthritic changes developing and significant pain that is
unresponsive, conservative treatment should be tried. If there are significant
changes that are unresponsive to rest and treatment within the short term,
then surgical options should be considered.
Older dogs should be
tried on conservative management first, and again if not responsive, surgical
options considered. The best responses are from total hip replacement,
but the cost is high. If this cannot be afforded, the age of the dog should
be considered, the older the dog, the more one leans to medical management,
the younger the dog with severe symptoms, the more a surgical option should
be considered.
GENETIC AND BREED
CONTROL ASPECTS OF HD
Genetic Aspects
Definition - Inherited
- this is the genetic material that is passed on to the next generation(s)
unchanged by - although the "expression of" may be altered by - the environment.
Inherited generally refers to trait(s) exhibited by the individual that
breeders are interested in. Occasionally it may be a breed fault that they
do not want exhibited eg. incorrect coat colour or texture; but mostly
breeders are interested in maintaining particular virtues, and at the same
time, removing the undesirable faults.
Where a condition is
affected by more than 3 genes, these are called polygenetic and are much
harder to clear from the population as the effects are often a blend of
the effects of the genes and the environment acting together. The more
genes that are involved, the greater is the chance that the environmental
factors will affect the end result. Environmental factors include diet,
rate of weight gain, level of activity, stress factors etc.
Breed Aspects in
relation to Control Schemes
Hip Dysplasia is a
polygenetic condition, ie. many genes affect the outcome. The more genes
affecting a characteristic, the harder and slower it is to eradicate or
affect the characteristic, and the more environmental effects come into
play (diet, weight, rate of growth etc). Where there are ways to measure
the condition, then progress can be made in controlling the effect of the
condition in the overall population eg. Hip Dysplasia - X raying of individuals
and their progeny.
The schemes currently
in use for control/reduction in severity of HD and ED aim to reduce the
incidence and overall severity of these conditions across the breed (a)
as a whole and (b) over time. Trying to shift the genetic structure of
polygenetic conditions within a breed is a long term goal, and cannot be
pushed rapidly without severe consequences in other areas (eg. type, temperament
etc).
The overall picture
must be considered. Trying to eliminate all dogs with hip dysplasia did
not work (attempted in both GSD's and Labradors), the end result was a
greatly reduced genetic pool, cases of HD still occurring and breeds that
did not resemble the standard. The main aim today of most hip schemes is
a gradual reduction in the breed average while at the same time allowing
breeders to preserve valuable bloodlines and decreasing the incidence of
really severe HD. The hereditability of HD varies in different breeds,
the higher the degree of inheritance, the more rapidly changes can occur
within a breed when selecting for that characteristic. Also, a dog that
has a good hip score, may not necessarily throw low scores in his progeny,
a full litter brother with a similar score may have a far lower progeny
average than his brother.
Until there are very
reliable breed specific DNA markers or gene tests, rapid change within
breeds, and therefore breed averages, will not be possible.
Population Means
and Spread (of any measurable factor)
Populations can be
described by a bell curve which can apply to any feature you wish to look
at, be it height through a breed, litter size, HD scores and so on. With
this curve, the top of the curve is the mean of the population factor being
assessed (eg. height) with the extremes at either end of the scale (eg.
the shortest and tallest).
Diagram of a Bell
(Normal) Curve
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Ideal Breed
Mean Size is at top of Normal Curve, ie at 62.5 cms.
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Breed
Population
-
Numbers
or
Percentage
or
Proportion
|
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Breed Selection
- Factors or Score or Value
|
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Proportional
Frequency Polygon for Normal Distribution (Normal Curve)
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If in German Shepherds
we apply this to height, and we have height limits on the breed; while
we wish to breed strong, well boned dogs (who generally are on the large
end of the scale), we have to fit (or attempt to fit) the vast majority
of dogs under the limit, so the breeders will usually discard the tallest
and the smallest, and generally work with the medium to large range of
the population.
This same principle
can be applied to any genetic problem within a breed. If the incidence
of a problem is small across the whole breed, eg. 5-10%, it can be fairly
easy for breeders or clubs to say not to breed with affected animals.
If, however, the problem has a variable expression and/or a complex means
(polygenetic) of inheritance, this can affect virtually every member of
a breed eg. Hip Dysplasia, to some degree.
HD X-Ray Control
Schemes
1. Grading –
where various aspects of hip construction, looseness of joints is looked
at and assessed. The current international grading system has 0-6 grades,
also called A-F (in some countries). The worst grade per hip gives the
overall grade (ie. if grade 0 in 1 hip and 3 in the other, the overall
grade is 3).
2. Scoring –
using the BVA System where 9 different areas of the hips are measured and
scored (generally out of a 0-6 scale). Total score per hip given as well
as overall total (maximum 106). Very useful in determining the breed average.
If combined with a grading system, again the hip with the highest score
will determine the overall grade (the ED scheme works on a similar score/overall
grade basis).
The Australian ‘A’
Stamp is given by the GSDCA for hips that have a total score of 8 or less
per hip, and are considered within normal limits of the breed and suitable
for breeding purposes.
3. PENN Hip
– dogs are anaesthetized and subjected to standard pressure, and then X
rayed, to determine the degree of joint laxity. Many breeds exhibit varying
degrees of joint laxity both across the breed and within the breed. The
relevance of the joint laxity when done at an early age (4-6 months) needs
to be seen relative to long term hip results (ie. against standardized
HD X-rays at 12-18 months of age. Some breeds are more “laxity tolerant”,
ie. the rate of change predicted is not as high in some breeds as others.
Breed Averages and
Medians
Breed Average
- means all the scores from all the submitted animals being totalled and
the divided to find the average for any member of a breed being checked
for that characteristic (HD) will have a result (score or grade) close
to that average score.
Breed Median
- a breed median is the result for that breed where 50% of the breed will
be better than that figure and 50% will be worse. In breeds where there
are smaller populations being scored, the breed average may be considerably
higher than the breed median. With increasing numbers (thousands) these
figures are considerably closer.
With HD Schemes, we
are working with empirical tests with large degrees of variability within
them, it is therefore essential that every breed be looked at from as broad
a spectrum as possible so that a relevant decisions can be made as to the
breed worth of that individual. As we discussed above, when looking at
a population, the spread of the population as well as the population mean
is essential if making decisions as to what one can afford to discard from
that population. Combined with this we need to estimate how many other
individuals that are being culled for various other reasons so that in
looking at a breed population as a whole, we need to retain at least 75%
of the population for any one characteristic being selected for.
When breeding, we obviously
wish to breed from the best, soundest dogs, but as started before, this
should be kept in perspective in relation to other genetic and breed soundness
characteristics that are necessary. For that reason, we generally breed
up to and often slightly past a breed average if we wish to retain sufficient
breeding stock for the overall health and viability of the breed.
When discussing HD
in the GSD, the breed average (BVA total score) is somewhere around 13
in Australia after some 20,000 dogs being scored/graded (the UK average
is 18.73). When allowing for differences per hip as well, the average score
per hip is around 7 to 8 (a maximum of Grade 3 if grading), a maximum of
8 per hip is allowed by our national governing body, the GSDCA if an A
stamp is issued, indicating that the overall quality of the hips are suitable
for breeding. As the total score per hip can go to a maximum of 53, a cut
off of 8 per hip is quite low.
In the GSD as the heritability
of HD is quite high, reasonably rapid improvements can be made, and generally
75% of the dogs submitted will pass these stringent requirements, indicating
that the spread of the population is reasonably narrow.
In other breeds the
breed average may be much higher, the inheritance lower and the population
spread much greater if one looks at the 75% of the population one wishes
to keep, eg. the Golden Retriever, current breed average around 20, this
mean has shifted very little despite hard work by breeders as well as breed
improvement schemes LRL’s for hips, elbows and eyes. In this breed one
would have to go to at least a score of 10 per hip if not slightly higher
in order to retain sufficient breeding stock across the board.
# If the breed
average is above 20, efforts should be made to select and breed from stock
under 20, as scores over 20 will generally result in significant arthritic
changes over time (ie. as the dog ages). Where superior individuals have
scores significantly higher, great care should be used if breeding from
these animals, ideally using partners will very low scores and preferably
where these partners have themselves already produced low scoring stock.
CORRECT USE OF THE
INHERITED DISEASES SCHEMES BY BREEDERS
The whole idea of these
schemes is to give breeders information so as to give them knowledge prior
to breeding an animal as to what one could afford to do.
BVA Scoring Scheme
- Obviously an animal with a higher score should be used with more care
and preferably to a sire or bitch of low score/grade and preferably where
there are known family or sire averages. This type of system works where
sire statistics are published, where the average score of the sire (where
more than 20 progeny are scored) is of greater accuracy in predicting the
average score of his progeny, than the score of the sire himself.
In the German Breed
Value Scheme – Breed values are assigned along similar lines, where
their data base encompasses litter mates, sire averages etc to give a more
complete breed value per individual and outcomes for any expected mating.
The breed values for an individual are out of 100, and the SV have gone
1 step further by saying that the combined breed value of the parent should
be less than 200. This appears to be working quite well.
The conclusion one
gets from these schemes, is that the more information one has both of the
parents themselves and of the close relative, particularly offspring of
the sire, the better one can plan and get successful results across a litter.
In breeds where such information is limited and/or sire statistics are
not available, breeders have much harder time selecting good sires and
good breeding combinations.
EXPECTATIONS OF
A NORMAL HIP
What is Normal
– Normal Grade or Normal/Average for that Breed.
Normal hips
are technically a 0/0, going up to around a maximum of 2-3 per hips.
Normal hips for a
specific breed - ie. average hip status, can be vary greatly between breeds.
Discussion
Technically by defining
a normal hip score or grade, makes any higher score or grade dysplastic.
However, an 8/8 hip for GSD is within the normal range of the Australian
breed average, just as a 10/10 score can be “normal/average” for a Golden
Retriever. We are often being penalized for breeding puppies that score
or grade above the normal grade, rarely is the breed average for that breed
considered. Legally we need to have a better definition of either what
are normal hips, or better define what is considered as soundness for breeding
purposes within that breed.
Age factors
- On looseness of ligamentation, just because a dog is loose at 6 months,
but otherwise has good joint anatomy (deep sockets, good femoral heads
and necks), it does not necessarily mean that the dog will be grossly dysplastic
by either 12 months or even by middle age. If a dog hips are within a normal
range or even slightly above average for that breed, and there are no signs
of lameness, should one interfere just because we can? Because of
that looseness, younger and younger dogs (puppies) are routinely being
considered for surgery.
Older dogs are similarly
being targeted for hip operations even where changes are minimal. Often
these dogs on further examination have either back (spondylitis) or other
conditions present and have been often “diagnosed” by breed alone.
CONCLUSION
In conclusion, with
increasing owner reliance on litigation, we as breeders (and the Kennel
Controls) need to develop a broader definition of normal in regard to breeding
stock. Is it within the normal breed average, that breeding stock should
be selected at or preferably below the breed average. Ideally sire statistics
should be looked at more carefully as well as sibling results. Broader
expectations should be given to the public explaining while we as breeders
can try as hard as possible to breed “normal” hips (and elbows), we can
occasionally turn up bad results due to the polygenetic basis of the conditions
we are looking at.
Similarly it would
be most prudent that breed clubs develop normal weight ranges for the differing
sexes at various ages, that can be handed out, so that novices (owners,
breeders and veterinarians alike) can be what is normal rate of weight
gain for that breed, sex and age. Large variations in weight above normal
are likely to exaggerate any inherited abnormalities of structure, particularly
looseness of ligamentation.
Back
to Index
ELBOW
DYSPLASIA
Elbow Dysplasia
Dr Karen Hedberg BVSc.
- 2002.
Elbow Dysplasia
(ED) - There are 4 main subgroups of elbow dysplasia, which may occur
alone or in combination. Generally they are considered inherited in most
breeds and the incidence may be adversely affected by incorrect diets in
some breeds. Excessive rate of weight gain can affect the incidence of
many elbow conditions, often leading to joint incongruity (uneven rate
of growth between the radius and ulna), and OCD seen particularly in males.
1. UAP - Ununited
Anconeal Process - The part of the elbow involved is a large triangular
shaped piece of bone situated at the back of the elbow joint. This has
a separate ossification center in a handful of breeds notably the GSD,
Labrador, Great Dane, Irish Wolfhound, Newfoundlands, Bloodhound, Basset
and Afghan hounds. The process normally is fully ossified (sealed) by 16-18
weeks of age. This condition is considered inherited with a possible 3
different genes being involved.
Symptoms - Clinically
signs are seen from as young as 5-6 months with often an intermittent lameness,
which is exaggerated by exercise. Full flexion and extension of the elbow
will elicit pain. There is often an accompanying lateral bursitis (fluid
swelling). X rays of the elbow in the flexed lateral position will readily
show whether the process has unified or not. Long standing cases often
have boney arthritic changes as well.
Treatment -
Either (a) removal of the process, if done while young, reasonable prognosis
with some arthritis later, or (b) fixation of the loose fragment by a lag
screw, for reasonable prognosis in early cases. As the anconeal process
is not a weight bearing surface, results following early surgery gives
much better long term prospects than in the FCP cases (as loss of that
process affects the weight bearing surfaces of the joint).
The majority of UAP
cases in the GSD have good congruity of the head of the radius relative
to the ulna. Where there is poor congruity, ie. the radius is too long
for the ulna, osteotomy (cutting) of the ulna to allow it to lengthen naturally
is another option.
Affected dogs should
not be breed from. UAP is generally considered to be inherited as a separate
condition from OCD and FCP in the GSD.
2. OCD - Osteochondrosis
Dessicans - this occurs in many larger breeds, almost any breed greater
than 18-20kg at adulthood. There is a higher incidence in males versus
females. This can affect many joints, the commonest being the elbow. Breeds
that see with a reasonably high incidence of elbow OCD would cover the
following :- Rottweiler (high incidence), GSD, Golden Retriever, St Bernard,
Great Dane, Border Collie, Rhodesian Ridgeback, Labrador.
Symptoms - Generally
seen as a shifting lameness in the forequarter from around 5-8 months of
age, some joint capsule swelling and usually a turning out of the front
legs at stance as the inner edges of the elbow are most commonly affected.
The cause of the problem is considered to be due to a faulty blood supply
to the joint cartilage secondary to very rapid growth. On X ray the signs
are often quite subtle in mild cases with minor “fluffiness” of the joint
surfaces to the more distinct pot holes of larger lesions. Generally diagnoses
of a straight extended and slightly medially rotated view of the elbow.
Treatment -
If this condition is mild, treatment with drugs such as Cartrophen which
increases the blood supply to cartilages, can be very effective along with
complete rest, slowing down of the rate of weight gain, and low doses of
anti-inflammatories. Repair and recovery can take up to 6-8 weeks of age
depending on the severity of the condition, very heavy puppies may have
to be kept reasonably restricted until 9 months of age by which stage all
rapid growth has slowed dramatically. Severe cases of OCD are often found
in conjunction with a FCP, and may require surgical intervention. Most
cases >80% show good responses to medical, dietary and exercise management.
3. FCP - Fragmented
Coronoid Process (of the Ulna) - this is generally referring to the
medial coronoid process, a process that stabilizes the medial edge of the
joint. Fragmentation of this process means that the inside edge of the
elbow is not stable, hence the very typical lateral rotation of the leg
away from the pain. Again, the same age group as above. On X ray the process
can be seen as separated on a plate with the elbow extended straight out
and a second view with slight medial rotation. If these are diagnosed when
young, surgical intervention gives reasonable results, in the older dog
where there are considerably secondary arthritic changes, medical management
with tablets if probably preferred. Regardless of the treatment, the resulting
joint incongruity (unevenness) will lead to ongoing osteoarthritis over
time.
4. Joint Incongruity
-
While most forms of elbow dysplasia can by their development result in
joint incongruity, here we are looking at where there has been a possible
early closure of a distal growth plate in the foreleg resulting in uneven
growth of the radius (usually slightly shorter) in relation to the ulna.
The resulting uneven ends of the bones within the joint can cause excessive
wear on cartilages and in the worst cases, force the anconeal process distally
(ie. create a UAP). Relatively uncommon in the GSD, however severe cases
require surgery.
Other forms of elbow
“dysplasia” exist, these forms generally involve the lateral displacement
of the top of the radius in relation to the ulna (giving a cabriole effect)
but these very rarely affect the GSD.
General Treatment
of Elbow Dysplasia - As with any painful bone disorder, regardless
of the age presented, common treatment is aimed at pain management, sensible
diet and weight control and a restricted, suitable exercise regime. Where
there are only minor changes in joint surfaces, medical management and
conservative treatment with anti-inflammatory agents and rest is generally
all that is needed. Those animals with UAP require surgical intervention
to minimise future arthritis. Dogs with FCP or those with loose cartilaginous
flaps, should in the younger dog be removed in order to minimise future
damage to the joint. However due to the incongruity of the joint, there
will be ongoing changes regardless. In the older dog with advanced arthritic
changes, medical management and conservative exercise regimes is generally
the preferred method of treatment.
Diet and Elbow Dysplasia
- While diet may not of itself create elbow dysplasia, it can affect the
severity OCD seen. Rapid weight gain will push factors such as joint congruity,
as well as blood supply to the cartilages within the joints.
Rule outs (differential
diagnosis) - Not all forelimb lameness is due to elbow dysplasia. Panosteitis
and simple injuries should be checked for, particularly where there is
a very sudden onset of lameness.
Controlling the
incidence of Elbow Dysplasia - As elbow dysplasia is highly inherited,
breeding from severely affected dogs should be heavily discouraged. Generally
dogs with a UAP, FCP and arthritis of greater than 5mm are not used for
breeding in the GSD in Australia. Breeding from dogs with mild changes
should ideally be to normal partners and preferably to lines with low incidences
of problems. As this is a group of highly inherited conditions, fairly
rapid improvements can be made over reasonably short periods of time.
Dogs with normal elbows
and those with Grade I and Grade II changes are given the ‘Z’ Stamp by
the GSDCA Council and are deemed to be within normal breeding limits for
the breed. Care should be taken in breeding with Grade II elbows, preferably
to normal status partners.
Back
to Index
ELBOW
DYSPLASIA CONTROL SCHEME REPORT
Elbow Dysplasia Control Scheme
Report
Joylene Neddermeyer.
- July 2004.
At the recent National
Breed Commission Meeting I delivered a lecture regarding the progeny results
of sires within the National German Shepherd Dog Council of Australia Elbow
Dysplasia Control Scheme. I am pleased to say that the lecture was very
well received by all of those present and it was requested that the results
be published in the Magazine and a copy of the tables circulated to all
Breed Surveyors and Member Clubs.
It was felt that the
tables would be very useful at breed surveys and to breeders especially
when considering selection of a breeding partner. The statistics I have
prepared are slightly different to those previously published and all sires
are presented in families. We are indeed very fortunate that Dr Eva Francis
has maintained a database which consists of all of the animals that have
participated in the scheme since its inception in 1993.
Statistics can change
within a time frame however some concern has been noted over the last few
years in regards to a steady increase in the number of failures and the
ratio of Normal, Grade One and Grade Two results in some States compared
to others. There
are definite traits in regards to lines that produce good elbow results
and those lines whose results should be better. While it shouldbe stated
that this is only one area to select a stud dog for those breeders that
need improvement in the elbow status it should come into consideration.
Breed Surveyors need
to be aware of the bloodlines or bloodline combinations that may create
problems with resultant progeny and I believe that the tables as presented
will enable not only breed surveyors, but the breeders to assess the overall
family picture. It is my intention to update these charts on a regular
basis. I
am sure that you will agree that the statistics speak for themselves however
it must be stressed once again that it is only one area of breed advice.
Also please remember that statistics drawn from a small number of animals
presented should really be of interest value and not lead to any major
conclusions.
The progeny results
for Hip Dysplasia as presented by the HD Registrar Mr Doug West have been
printed in the Magazine and all breeders should combine the two sets of
results for a balanced view.
Once again thank you
to all of the breeders that have supported the German Shepherd Dog Council
of Australia Breed Improvement Schemes for a number of years which have
enabled us to offer a German Shepherd puppy for sale which is sounder in
both mind and body.
J.M. Neddermeyer
National Breed Commission
Chairman.
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GERMAN SHEPHERD
DOG COUNCIL OF AUSTRALIA : ELBOW DYSPLASIA CONTROL SCHEME
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Progeny results of Sires with more than 10 progeny
submitted to the scheme according to bloodlines.
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An asterisk ( * ) signifies a Grade and UAP in the
same dog.
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Data current to 30 June 2004.
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FEDOR
GRUNEN LUCKENER BLOODLINE. |
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Name
of Sire |
Grade |
%Normal |
%Grade
1 |
%Grade
2 |
%Grade
3 |
%
UAP |
No
of Prog |
No
of Dams |
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EDLENBLUT
ORKAN |
no
result |
55 |
28 |
17 |
0 |
0 |
18 |
15 |
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Karlrach
Run About |
no
score |
55 |
0 |
27 |
9 |
9 |
11 |
9 |
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Maltaknights
Grandmaster |
Two |
48 |
24 |
28 |
0 |
0 |
25 |
19 |
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