Health testing is a very important part of breeding boxers and more people need to be aware. This page provides an explanation of genetic disease and descriptions of those diseases prevalent in boxers, followed by a list of the tests available to screen for those diseases and determine genetic fitness for breeding.
The American Boxer Club’s recommended health screening programme for breeding boxers can be viewed at http://www.americanboxerclub.org/health-screening.html
What is a genetic disease?
A genetic disorder is one in which an abnormality in the genetic make-up (the genome) of the individual plays a significant role in causing a disease or condition. While some disorders can occur as the result of spontaneous mutation, most genetic disorders are inherited. These diseases are heart-breaking because they can impact severely on the quality and length of life of the affected dog - who is generally a well-loved family member by the time the condition is apparent.
The frequency of inherited conditions can be greatly reduced through good breeding practices. For this to occur, we need to know how the disease is inherited, how to identify the condition as early as possible, and ways to recognize carriers of the disease who are not clinically affected. Where testing regimes are available, it is important that all potential breeding stock are screened. Animals found to be affected by, or are carriers of a disease should not used for breeding.
Genetically inheritable diseases prevalent in boxers
Boxer cardiomyopathy is a distinct disease from the dilated cardiomyopathy common in some other breeds. Other names for BCM are Boxer Arrythmic Cardiomyopathy (BAC), Familial Ventricular Arrhythmia (FVA) and Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC).
Hip dysplasia has polygenic inheritance, meaning it is caused by the inheritance of multiple genes. It is not yet known how many, or which genes are involved. Factors that can make the disease worse include excess weight, excess or prolonged exercise before maturity, a fast growth rate, and high-calorie or supplemented diets.
Demodectic mange can occur in localised form, which is characterised by a few spots that do not itch. These patchs usually appear on head, neck and fore limbs. Ninety percent of those puppies that develop localised demodex will heal on their own. Ten percent of those puppies will go on to have generalised demodex.
Dogs most susceptible to bloat are the large, deep-chested breeds, in whom the stomach appears to be more mobile within the abdomen. Risk factors are: hereditary predisposition, over-eating (large meals), rapid eating, raised feeders, pre-moistening of dry food preserved with citric acid, feeding dry food with a fat in the top four ingredients. The risk of bloat increases with age. Feeding a food with a rendered meat ingredient, inclusive of bone, in the first four ingredients decreases the risk of bloat.
The Purdue veterinary research team, who conducted a research study in 2000 into the risk factors associated with bloat concluded these are the things you can do to help prevent bloat:
a.. The strongest recommendation to prevent GVD (bloat) should be to not breed a dog that has a first degree relative that has had bloat. This places a special responsibility on an owner to inform the breeder should their dog bloat.
b.. Do not raise the feeding dish.
c.. SLOW the dog's speed of eating.
Tests available to screen for serious genetic diseases and which should be undertaken on all breeding boxers
Holter Monitor: A 24-hour EKG (electrocardiogram) that
tests for the presence of PVCs (Premature Ventricular
Contractions). This test screens for Boxer Arrythmic
Cardiomyopathy, and should be repeated yearly. There is, at
this time, no set number of PVCs that would be considered
"affected" with BAC. A zero or low number of PVCs does not
mean that the dog is free of BAC, it only means that the dog
was not exhibiting PVCs during that 24-hour period. However,
consistent zero/low readings on yearly Holtering would
indicate a higher possibility that the dog is not affected
For more information, please visit http://www.americanboxerclub.org/healthtbc.html and read these articles: Reports From The Health And Research Committee, May 2000; Information on Boxer Cardiomyopathy; Report and Article by Dr. Meurs; Article on Boxer Cardiomyopathy; Information on Holter monitoring.
Doppler Echocardiogram: An ultrasound of the heart that detects abnormal flow velocities and allows for the diagnosis and quantification of the severity of Aortic Stenosis. A clear Doppler after the dog is 24 months of age is considered conclusive (the dog does not have AS). Some studies show that Aortic Stenosis is a polygentic (cause by several genes) disease, so two clear parents can produce affected offspring.
Cardiac Auscultation: A stethoscopic examination of the heart that detects murmurs that may be indicative of AS. According to the UK Breed Council Control Scheme, a dog that is found to have no murmur or a Grade 1 murmur upon auscultation after 12 months of age is considered normal and acceptable for breeding.
OFA Heart: The OFA will certify dogs as "normal" if
they are found, upon ausculatation after 12 months of age, to
be without a cardiac murmur, or with an innocent heart murmur
that is found to be otherwise normal by virtue of an
echocardiographic examination which includes Doppler studies.
Screening can be done by a general practice veterinarian, a
specialist, or a cardiologist. Submission of results is
voluntary. OFA Heart testing may detect Aortic Stenosis,
although mild cases may go unnoticed if auscultation is
performed by a general practice vet. It will not detect Boxer
OFA has developed a database registry for Holter Monitor results for the Boxer breed. Submission of results is voluntary and they are confidential.
For more information on all OFA tests, please visit http://www.offa.org/
**All heart testing should be performed by a board-certified veterinary cardiologist.**
OFA Hips (Orthopedic Foundation for Animals Inc): An X-ray of the pelvic joint to screen for hip dysplasia. Ratings of "Excellent," "Good," or "Fair" are considered to be free of HD. One view is taken, the dog is commonly sedated or anesthetized but this is not required, and submission of results is voluntary. The X-rays must be taken after the dog is 24 months of age. There are several other factors that influence the expression of HD, including diet and environment, and two clear parents can produce dysplastic puppies.
PennHip (University of Pennsylvania Hip Improvement Program): An X-ray of the pelvic joint to screen for hip dysplasia. Laxity of the hips is evaluated and compared to the breed average (the Boxer breed average is .48 laxity). Three views are taken, the dog must be sedated or anesthetized, and submission of results is mandatory. PennHip X-rays can be taken as early as 16 weeks, although most feel a definitive rating should wait until the dog is older.
OFA Thyroid: A blood test to detect autoimmune thyroiditis. Annual testing through 4 years of age is recommended, after that, testing every other year should suffice. A negative at any one time will not guarantee that the dog will not develop thyroiditis. Most vets do not perform a full thyroid panel - as a result, there are only six laboratories that are approved for OFA thyroid certification: the veterinary laboraties at Michigan State University, Cornell University, University of Guelph, University of Minnesota, University of California - Davis, and Texas A&M University.
CERF (Canine Eye Registration Foundation) testing screens for heritable eye diseases such as PRA (Progessive Retinal Atrophy). Results are kept in a centralized, national registry. Testing must be performed by a member of the American College of Veterinary Ophthalmologists. Submission of results is mandatory but confidential. CERF screening is repeated yearly.
If you want to discuss about these topics, visit our Boxer Health and Puppy Matters forums.