Health Clearances and Concerns
This is an explanation of health issues that Labradors are prone to. Some of them have tests that
are available and others do not. I am giving my personal opinions on each and
this should give you extensive insight into our program and how
careful we are concerning genetic health.
Hips, Elbows and Patellas ~
OFA (Orthopedic Foundation for Animals) is what the majority of breeders use in order to
determine the hip and elbow health of a Labrador to see if it should be allowed to reproduce.
They are an outstanding not-for-profit organization that has funded $3 million in research aimed
at reducing the incidents of genetic disorders. Unfortunately I feel there are more accurate
methods that have been scientifically proven to reduce the occurrence of
genetic issues if used and/or that give you a much more detailed result.
My turning point came recently when I submitted hip and elbow films on a Labrador that I
purchased. She had just turned two years and though she did not show any outward signs of
hip dysphasia when my vet and I looked at the hip films we were sure they would not pass.
The femoral neck was a bit thick, the ball was flattened and it was not set in a deep socket.
One hip should have been fair and the other borderline for hip dysplasia. I scanned the films
and emailed them to several breeder friends and they all agreed she would not pass.
When I received the OFA results back she received a normal elbow rating and GOOD hips. I was
very surprised. I called Dr. Keller at OFA to discuss the matter. Though he could not see the
actual films (as each film is mailed to three vets on the OFA
board at random for a rating), he did say that each vet gave a good rating with no additional
notes. I didn’t care what rating OFA gave her, in my heart I knew that she should not be bred
and so I had her spay and she was placed in a pet home. If the OFA
rating is the guideline you are supposed to use in order to determine the breeding quality
of a Labrador I could have kept this girl and bred her and everyone (according to what OFA said)
would have thought I was being an ethical and responsible breeder. I do not agree. Being
“experts” I was seriously disheartened as I didn’t see how they could have passed those as her
PennHip was horrible (more about that below).
The best way to determine hip quality on an adult is by submitting to PennHip and also viewing
(if you know what you are looking at) an OFA positioning of the hips as well. Though PennHip boasts
that they can determine the future hip quality on a puppy over 16 weeks with great
accuracy but I do not support this and only rely on what I see personally and what PennHip
says about the radiographs of an adult.
Elbows are the trickier of the two to evaluate and though I have seen countless elbow films I only
have a moderate grasp as to what I am seeing. I know what to look for, but the films are some times
difficult to read and so it takes a very skilled person to read these films. OFA again is the choice
that most breeders use and since I am reluctant to use them for hips I would prefer to use another
diagnostic approach for elbows.
The most common genetic issue in Labradors now is not hip dysphasia. It is FCP (fragmented medial
coronoid process) of the elbow. FCP is where a piece of cartilage breaks off and floats around in
the elbow causing swelling and lameness. Some times because of the positioning that OFA uses they
are unable to see a small piece of cartilage and pass the animal. The animals are then used for
breeding and pass the possibility of a genetic issue on to their offspring at a greater risk. OFA
is the only "acceptable" way of evaluating elbows right now but North Carolina State University
has perfected a positioning called DIMPLO. It is a new positioning at a 35 degree angle and they
can detect issues like FCP very easily. It is pretty impressive but also very expensive. There
were hopes that the new DIMPLO positioning would eventually be offered by PennHip or OFA but I
do not see any progress in that department. In order to get the DIMPLO view it must be done at
NCSU and that is very expensive and some times simply impossible time wise.
I have instead decided to have MRI’s done on the elbows of my Labradors and that is the ultimate
diagnostic tool. The down side is still the cost but the travel is reduced. Also, since it is a
procedure only and not a registry tool they do not provide me with an official paper that says
“pass” or “fail”. I have been presented with a bill and list of procedure and that is about it.
When I have asked them for something in writing they provide me with some scribble on the bottom
of the bill that says something like “No evidence” and that looks less than
official. That may be a problem in the future but for now I am satisfied and know I am doing more
than what is required of me as a breeder to reduce issues in my line and the breed and I am proud
to say that my precentage is way below national average.
A Patella (knee cap) that slips out of place is easy to diagnose. The rear leg is bent and the patella
is moved side to side to see if it slips out of position. If they can it is called slipped stifle
and is very rare and usual in Labradors but fairly common in toy breeds. Normally slipped stifle
in a Labrador begins as a limp because of an injury. To date I have produced one Labrador that was
diagnosed with this issue and there have been no others. All of my dogs are checked and are clear of the
disorder.
~ Eyes ~
Each Labrador should be seen yearly by a Canine Ophthalmologist and examined for eye issues.
This test is called a CERF (Canine Eye Registration Foundation) test and only a specialist can
perform it. The veterinarian administers drops that dilate the eye and they use a special scope
to look into the back of the eye to see if there are abnormalities of the retina or other issues
present such as cataracts or ulcerations. They also examine the outside of the eye for abnormalities.
Besides the CERF exam there are blood tests available for the following two eye disorders that should
be used accordingly.
PRA (Progressive Retinal Atrophy) causes the blood flow into the eye to become diminished and
causes either full, partial or night blindness. The Optigen company began offering a “marker”
test for PRA in 2001 and Labrador breeders rushed out to get all of their dogs tested and were
horrified to find that there were quite a few dogs that were affected (were partially bind) with
this blinding eye disorder and a very large number that were carriers. They of course neutered
all of the affected dogs and even some carriers. It was a large blow to the Labrador community
and was quite horrifying. About a year later they announced that the inheritance was more
complicated than they originally anticipated and that an updated “mutation” version of the test
was now released that would not give false results! Oops! It is very important that at least
one parent of the puppy you are considering is PRA/PRcd normal (non-carrier) as they are unable
to produce a puppy that has PRA no matter who they are bred to. I do have to ad a side note that
other companies do offer this test and if you are a breeder I would discourage you from using anyone but
Optigen for your testing. Contact me if you would like more information.
There are other tests such as RD (Retinal Dysphasia) and OSD (Ocular Skeletal Dysplasia) which
are available. RD is primarily in Labradors from European decent, it is very rare and is described
as clumps or folds of tissue on the retina that cause blind spots. The more severe and fully
genetic type is OSD is found in Labradors from American decent. In the more severe case of OSD
physical dwarfism is present. RD can also be caused from vitamin A deficiency, virus exposure,
trauma, treatment of the dam or puppy with certain drugs and can be a standard physical defect
not caused by inheritance.
The lower eye lid in Labradors can be affected with Entropian or Ectropian. Ectropian is when
the eye lid turns inwards and the lashes rub against the eye. Ectropian is when the lid is
turned out exposing the inner surface. Both of these normally make the individual prone to
eye infections and may require surgery.
~ Neurological and Muscular ~
There is a new test for EIC (exercised induced collapse) that is now offered. Most, but not
all, affected dogs have been from field-trial breedings or dogs in which field lines have been
introduced in the pedigree. Signs first become apparent in young dogs - usually between 5 months
and 3 years of age (average 14 months). In dogs used for field trials, this usually coincides
with the age at which they enter heavy training. Littermates and other related dogs are commonly
affected but depending on their temperament and lifestyle they may or may not manifest symptoms.
Affected dogs exhibiting symptoms of collapse are usually described as having an excitable
temperament and lots of drive.
The first thing noted is usually a rocking or forced gait. The rear limbs then become weak and unable
to support weight. Many affected dogs will appear uncoordinated or continue to run while dragging
their back legs. In some dogs the rear limb collapse progresses to forelimb weakness and occasionally
to a total inability to move. Some dogs appear to have a loss of balance and may fall over, particularly
as they recover from complete collapse. Most collapsed dogs are totally conscious and alert, still
trying to run and retrieve but as many as 25% of affected dogs will appear stunned or disoriented
during the episode. It is common for the symptoms to worsen for 3 to 5 minutes even after exercise
has been terminated. As you can see EIC should not to be taken lightly.
The company that offers the EIC test claims that show bred English Labs can have EIC and at first
I did not see how that was possible. To this day I have not owned, produced or seen an English Labrador
that actually has the disorder and the show Labrador community wasn’t one to keep quiet about genetic
issues. I went a very long time without hearing of any dogs that were affected by this but now I am hearing
from a very trusted source that though it is very rare it is out there. The more I have read the more I
feel that EIC testing should be done...but the test is so new. Remember what happened
the last time I mentioned a new test? New or not I feel all bases should be covered
no matter if I have seen or produced this issue or not. We test for heart, thyroid and other things that are not
problematic as well so why not EIC? I think it is a good choice and so we will begin testing shortly.
CNM (Centronuclear Myopathy) is just like EIC where it is only in American field lines. They say
that it is also in English lines but since symptoms start showing up at around 2 weeks of age with
progressive significant weight loss followed by absence of tendon reflexes at around one month of age
and nothing has surfaced I would have to say that that is incorrect information. This issue is much
worse in my opinion than EIC and if I were to choose any issue (that isn't an issue) to test for
this would be it. Any Labrador that has anything other than 100% English type show blood in their
pedigrees should have this test.
Narcolepsy is also a disorder listed as a problem in Labradors as a breed, but again, I have
never seen it besides in video. It is a disabling sleep disorder that is characterized by daytime sleepiness,
cataplexy and striking transition from wakefulness into REM (Rapid Eye Movement) sleep. A dog can
literally be running and fall over in deep sleep. It is a very dangerous illness and there is now a
reliable blood test for the issue which is inherited as a simple recessive. That means that both parents
must be a carrier in order to produce offspring that is affected by narcolepsy.
Megaesophagus is so-named because of the enlargement of the esophagus caused by the loss of peristaltic
function. (Peristalsis is the process of muscular contractions that move food through the esophagus.)
Dogs with megaesophagus will usually regurgitate their food soon after eating. It is often seen in young
puppies, but may develop later in life. Other signs include labored breathing (possibly aspiration
pneumonia), fever, lethargy, and nasal discharge. Some dogs may outgrow this condition, while there
is no improvement in other dogs.
To confirm the diagnosis, your veterinarian may decide to take chest x-rays, run blood tests, and run a
urinalysis. Although there is no specific treatment for megaesophagus, your veterinarian may be
able to identify an underlying cause and provide supportive care. Feeding small, frequent,
high-caloric meals from an elevated stand may also help.
In Labs, the condition appears to be genetic, however the mode of inheritance is still unknown.
In some breeds it is caused by a recessive gene and in other breeds it is caused by a dominant gene.
Until more is known about this condition, it is safest to avoid breeding any affected dogs,
their parents and their siblings. There is no test for this disorder and though it is very rare it can occur.
~ Heart ~
The EIC scare kind of reminds me of the TVD (Tricuspid Valve Dysplasia) situation that happened
many years ago. There was a single Champion that was said to have had this issue, though his owner
could provide proper heart clearances and he had never passed the issue on to his children. No one
had heard of that disorder at the time either and everyone flocked to their vets to get EKG’s and
heart clearances. At the time only a hand full of dogs came back as having the issue and it seemed
to be a big waste of time. Today I have changed my mind after seeing a friend that purchased two
Labrador puppies that are considered primarily unrelated but both affected with the disorder. It
is still very rare and I have not seen it in my line but have decided that I have heard enough of
the issue to keep me up nights and so we started doing the heart clearances.
Because studies have
shown that TVD has been identified in dogs within the same litter researchers at UC-Davis think it
may be genetic, but on the other hand there are no studies that show that certain lines carry the
problem. The statistics are the same from related or unrelated dogs and so they have no idea if it
is genetic. It could just be a combination of the genes in particular breeding that produce the TVD
results.
When the puppies heart grows while still in the womb the tricuspid valve is kept open by
connective tissue. In order for the heart to work properly there must be some cellular
degeneration. If that degeneration does not occur the valve will stay open to dome degree
causing TVD. TVD is diagnosed as a murmur, but though heart issues in general are rare, some
puppies do have a slight murmur when they are young that quickly disappears by the time he
or she reaches around 10 weeks of age, no longer than 6 months. If the murmur does not disappear
quickly the puppy should be given an ECG or Doppler to determine if it is TVD. A sonogram can
also be used for detection as the right side of the heart tends to become larger than the left
due to being over worked but that usually isn't a great way to detect a problem unless the
Labrador is an adult. To date we have had a couple of pups have the murmur up until 9 weeks
but have not had a murmur past that point in any of our pups. Any puppy that has ANY sort of
murmur as a puppy is not kept to show or breed later no matter how insignificant. We have also
ECGed pups if there is any question just to make sure and since a silent murmur can be present
the ECG is the best way to determine if there is TVD present. We have begun to get official
heart clearances on all of our adults. The only difference between that and what we are already
doing is we have the paperwork to submit to OFA if we want to, but you know how I love OFA.
The Cincinnati Children’s Hospital is working on isolating the gene so that a genetic test can
be offered in the near future.
~ Hormonal ~
Hypothyroidism can occurs when the thyroid gland does not secrete enough of the thyroid hormone
called thyroxine (T4). T4 plays a major role in controlling metabolism and is necessary for growth.
The most common cause of hypothyroidism is autoimmune thyroiditis. This occurs when the body
makes antibodies against the thyroid gland which gradually destroys the gland and decreases
its ability to secrete T4.
Because T4 affects many internal organs a deficiency can manifest with varied symptoms.
Some possible symptoms include obesity, lethargy, mental dullness, hair loss, hyperpigmentation
(darkening of the skin), mood swings, facial paralysis, and disorientation. Other possible symptoms
include diarrhea, constipation, vomiting, abnormal heat cycles, lowered body temperature and even
heart problems. One study found that the majority of dogs with hypothyroidism had some kind of skin
abnormality, however some dogs may not have any symptoms. All of our dogs are given this simple test.
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