Re: Breeding

Home Main Forums Dogs Where can I find ……? Breeding Re: Breeding

#75808
Anonymous
Guest

Well as I have already said the studying and learning comes before the breeding and it is a  breed even the expert tread very carefully has your bitch had all the health checks lets start with the ones I know and this is not my breed

Boxer cardiomyopathy as we know it consists primarily of an electrical conduction disorder which causes the heart to beat erratically (to have an arrhythmia) some of the time. If the erratic beats occur infrequently and singly, the dog will probably not have symptoms of heart disease. If the erratic beats occur in sequence, weakness, collapse or sudden death may result. These arrhythmias may or may not be detected by listening to the heart with a stethoscope.

Whether or not they are detected depends on the frequency of the abnormal rhythm. If frequent, they can easily be heard with a stethoscope. The arrhythmia usually consists of VPCs (ventricular premature contractions) that are heard as an extra beat or a skipped beat that do not have a corresponding pulse. To identify these, the listener must therefore have one hand on the stethoscope holding it to the chest and one hand feeling for a pulse (usually at the femoral artery on the inside of the hind leg). In the normal functioning heart, there is a pulse for every beat that is heard.

When a VPC occurs, a beat is heard through the stethoscope (and it sounds like a stutter as it is not in the normal rhythm sequence of the sinus beats), but there is no pulse to go with it. These VPCs have a characteristic pattern on an ECG and this is the way they are confirmed. Often this is the first abnormality noticed in a boxer with cardiomyopathy. Usually the dog is having no symptoms of heart disease when these are noticed by a veterinarian during a routine exam. If the frequency of these irregular beats increases, the animal may suffer “fainting” spells (called syncopal episodes). This happens because these abnormal beats do not pump the blood effectively (no corresponding pulse) to the vital organs like a normal beat does and the brain becomes oxygen deprived while the abnormal beats are occuring.

Usually when an animal faints, they are having what is known as a run (several in a row) of VPCs. If the heart corrects itself, the animal regains consciousness in a matter of seconds to minutes. If the run of VPCs continues, this is termed ventricular tachycardia and can lead to the development of ventricular fibrillation which is fatal if the rhythm is not converted. This ventricular fibrillation (V-fib) is the cause of sudden death in most boxers with cardiomyopathy. There is no blood being pumped through the body when the animal is in V-fib.

Cardiomyopathy can also be responsible for sudden death associated with anesthesia. Now, just because a boxer has VPCs does not absolutely mean it has cardiomyopathy IF there is another disease process at work. I have seen animals with severe infection or cancer have VPCs that resolved completely once the infection was cleared or the malignancy removed. If, however, VPCs are seen in an otherwise healthy boxer, one would have a high index of suspicion for cardiomyopathy because of the prevalence of the disease in the boxer breed.

Some boxers with cardiomyopathy will enter another phase of disease where the ventricles of the heart start to dilate. At this time it is unclear whether this is a progression of the electrical conduction disorder, a separate disease more like that seen in other large breed dogs, or a subset of boxer CM that is not necessarily a progression of the previously arrhythmic dogs. With this condition, the walls of the heart become thin, the heart muscle weakens and these animals can show symptoms of heart failure such as coughing (from lung congestion) and/or fluid retention in the abdomen (ascites) depending on which side of the heart is most affected.

In time as the heart becomes very enlarged it begins to be an inefficient pump and dogs so affected may require numerous medications to keep the heart functioning well enough to sustain life. Still, most boxers affected with cardiomyopathy will ultimately die of their arrhythmia, not of congestive heart failure. The only way to definitively make the diagnosis of cardiomyopathy is to have a veterinary pathologist evaluate tissue samples from the heart muscle after death.

How is it diagnosed?
The best way to evaluate a boxer for arrhythmia is to use a 24 hour ECG called a Holter monitor. While an ECG can pick up arrhythmias if they are very frequent, the Holter is much better at doing so. It will tell you if your dog has VPCs, whether they are frequent or infrequent, single or multiple, from a single focus in the heart or from several sites.

Brain tumors in the Boxer
A team of scientists at the College of Veterinary Medicine at North Carolina State University (NCSU) is working hard to better understand brain tumors in Boxers. Ultimately, the scientists hope to develop effective new treatment options.

Boxers and other brachycephalic, or short-nosed, breeds have the highest incidence for a type of brain tumor known as gliomas. These tumors start in glial cells (supporting cells) within the brain, and as they grow they cause compression and death of surrounding brain tissue. The tumors can vary in malignancy from slow-growing, relatively benign tumors to high-grade, aggressive tumors known as glioblastoma multiforme. These latter tumors are resistant to current forms of treatment.

Led by Natasha Olby, D.V.M., Ph.D., assistant professor of neurology, the research team at NCSU is focusing on learning what makes tumors grow with the hope that targeting these “growth factors” will provide effective treatment options. There already has been a lot of work done on this type of brain tumor in people, as high-grade gliomas are the leading cause of death among humans with brain tumors.

“In our preliminary work, we’ve found that the pattern of growth in canine brain tumors is comparable to that seen in human brain tumors,” Olby says. “For example, we have found that the epidermal growth factor receptor, a receptor important in mediating tumor growth, is expressed at high levels by high-grade gliomas in dogs as well as people. Blocking the function of this receptor may therefore prevent or slow brain tumor growth, and we plan to investigate the ability of different drugs to achieve this effect.”

DM in the Boxer
Degenerative myelopathy (DM), a potentially debilitating neurological condition that can eventually paralyze its victims, can occur with relative frequency in Boxers. Unfortunately, the cause of DM remains unknown, although researchers in both clinical and basic sciences are working to find answers.

What is particularly frustrating is that signs of the condition — progressive spinal weakness and paralysis — do not usually appear until later in life, after a dog has been used in a breeding program.

Understanding DM
Degenerative myelopathy has been described as a degenerative neurological condition. Because there is no screening test, DM is considered a “rule-out” condition in which other mimicking conditions, such as a disc condition or tumors, must be eliminated, leaving DM as the conclusion. At present, a definitive identification of DM can only be determined post-mortem.

Signs usually appear when a dog is between 5 and 9 years old. It begins with a loss of coordination in the hind legs. The dog may wobble or drag its feet. The condition generally results in rear leg paralysis in approximately three to six months, foreleg paralysis in about another three to six months, and respiratory failure approximately three to six months later.

No pain appears to be associated with the paralysis, other than the dog wanting to continue life as before but being unable to. Both sexes appear to be equally affected.

HD in the Boxer

The following health conditions have been identified in the Boxer. Some of these conditions can be identified through testing. In those cases, the currently available tests have been listed and described. The text below is intended as an aid to those seeking health information and should not be used to form a diagnosis or to replace regular veterinary care by one’s own veterinarian.

Hip Dysplasia
Hip dysplasia is the number one cause of hind limb lameness in dogs and results in an arthritic condition of the hip joint which is initially caused by a laxity (looseness) in the hip joint itself. This joint is a ball and socket joint in which the head of the thigh bone (femur) fits into a cup-like depression (acetabulum) in the pelvis. The laxity is associated with the tissues which surround and hold the joint in place, that is, the tendons, ligaments, connective tissue, and muscle, and this laxity leads to bony abnormalities of the ball and socket. While the laxity of the joint is not thought to change much with time, the presence of joint instability causes abnomal wear and tear on the cartilage lining of the joint with subsequent development of arthritis as the dog ages.

Indeed, the Orthopedic Foundation for Animals (OFA) believes that there is little change in the test for dysplasia after 4 months of age; however, they require testing at two years of age or older for certification purposes, to err on the side of caution.Clinical signs can be extremely variable — from no symptoms to severe lameness. Severity of arthritic changes on radiographs (X-rays) does not necessarily correlate with degree of lameness.

Diagnosis is made from radiographs of the hip joint (from the pelvis to the kneecap) and does require sedation or anesthesia. Positioning of the dog is critical for proper evaluation. The radiographs are evaluated by veterinary radiologists specially trained for this task. The dogs are graded as excellent, good, fair, borderline, or mildly, moderately, or severely dysplastic.

Thyroid Disease in Boxers
Thyroid disease in the boxer occurs primarily as hypothyroidism, or impaired thyroid gland function with low thyroid hormone levels. It often develops slowly over several months or years. The animal’s body, for as yet unknown reasons, forms antibodies against its own thyroid gland resulting in partial or complete destruction of the gland and the subsequent inability to produce adequate thyroid hormone.

Many breeds, including the boxer, seem to be genetically predisposed to hypothyroidism. Affected animals may be listless, develop coarse haircoats, have significant hair loss, gain weight, experience infertility and/or fetal resorption or show neurologic problems. In some cases, abnormal test results may preceed the clinically apparent stage of the disease._ A_simple thyroid test (T4) obtained from your veterinarian is often inaccurate and can give falsely low readings in normal dogs with concurrent non-thyroid illness and normal values when thyroid disease is in the early stages.

More definitive testing may be obtained by performing a panel of tests which include Total T4, TGAA (thyroglobulin autoantibodies), cTSH (canine thyroid stimulating hormone), so-called “free T4 by equilibrium dialysis,” and sometimes T3 and free T3. This panel is currently not available from all diagnostic laboratories and must be sent to one of several reference laboratories by your veterinarian._ Repeat testing may be recommended at regular intervals, because the disease can be slow to develop and current test results may not predict future abnormalities. Your veterinarian may not feel the need for these additional tests if the dog has no clinical signs of hypothyroidism, but owners who suspect their animals of being hypothyroid despite normal values on simple T4 tests and/or those who suspect_an hereditary condition due to knowledge of affected relatives may wish to pursue more definitive testing as a screening mechanism in consultation with their veterinarian.

Aortic / Subaortic Valvular Stenosis: AS/SAS
One of the most common heart defects occurring in dogs, boxers in particular, is aortic or subaortic stenosis. In most cases the stenosis, or narrowing, is produced by a fibrous ring of tissue below the aortic valve, hence the term “subaortic.” The disease is inherited but its mode of transmission is not known at this time.

Oxygen-rich blood flows from the left ventricle of the heart, through the aortic valve and into the aorta, which transports the oxygenated blood to all organs and tissues in the body except the lungs. Narrowing of the aortic valve requires the left ventricle to work harder to pump the necessary amount of blood. This increased workload can result in hypertrophy (thickening) of the left heart muscle. Since the blood is being forced through a smaller-than-normal opening, there is also increased pressure generated by the pumping action of the heart. This increase in pressure can cause dilation (ballooning) of the aorta. Reduced flow can produce symptoms of fainting (syncope) and even sudden death, although abnormal heart rhythms (arrhythmias) may also contribute to these symptoms.

The stenosis creates a change in the flow of blood through the valve causing turbulence which results in swishing sound called a heart murmur. Often the stenosis can be seen on echocardiography. Murmurs are graded from one to six, but a weak murmur may not always be detectable, even by a trained cardiologist. Exercising the dog during the cardiac exam may increase detection of murmurs in some cases. Not all murmurs are the result of aortic stenosis/subaortic stenosis, but may be so-called “innocent,” or physiologic murmurs, particularly when they occur in young animals.

The diagnosis of AS/SAS is best made by a veterinary cardiologist, or one with equivalent experience and training. When a murmur is identified and not presumed to be physiologic, further investigation is warranted. The least invasive and most available testing consists of Echo/Doppler.This testing is best performed when the animal is full grown or at least one year of age, unless the dog is experiencing symptoms of heart disease, in which case testing should be pursued promptly.

Hope this makes good reading and maybe you will then understand why the studying of a breed comes way before the word breeding
Val

[quote author=nala link=topic=853.msg12389#msg12389 date=1123969403]
That it was i meant i mean everyone has to start somewhere and if people are just going to put people off breeding then we would not be where we are today.

I am not questioning anyone but people have to take a step back and look at what people are asking of them before going in and saying dont start breeding unless, there are a lot of things people shouldn’t do but if that was the case how boring would we be.
[/quote]

Do NOT follow this link or you will be banned from the site!