Health Testing — Majestueux Kennels

What does health testing mean for the pet owner?

In general, the risk of a hereditary condition is lower when both parents have tested clear for the condition. However, it's important to keep in mind that not all genetic mutations associated with a condition can be detected by current testing methods, and some genetic mutations may arise spontaneously in an individual with no family history of the condition.

Therefore, while the absence of a known genetic mutation in both parents may suggest a lower risk of hereditary transmission, it does not completely rule out the possibility of the condition being passed on to their offspring. Additionally, other factors such as environmental factors, age, and other genetic factors may also influence the development of the condition.

While conducting health tests and genetic screening can greatly reduce the likelihood of certain health issues in offspring, it does not guarantee that all offspring will be completely healthy.

Health testing and genetic screening are important tools in breeding to help ensure that potential health issues are identified and minimised. However, breeding involves the combination of genetic material from two individuals, and there is always a degree of genetic variation and unpredictability in the offspring.

It is possible that offspring may inherit a genetic mutation associated with a health issue that was not detected in the health tests or genetic screening conducted on the parents. Additionally, environmental factors and other genetic factors may also influence the development of certain health issues in offspring.

Therefore, it's important to continue to monitor the health of offspring and provide appropriate veterinary care to help minimise the risk of health issues. It's also important to work with a veterinarian and/or a professional breeder who has experience with the breed and can provide guidance on breeding practices to help maintain the health and well-being of the dogs and their offspring.

From a breeder's perspective, it is understood that animals are complex living beings composed of a diverse array of DNA sequences that dictate their physical attributes, mental characteristics, and overall health status. While comprehensive health testing is certainly a crucial aspect of responsible breeding practices, it is important to recognise that even the most rigorous testing cannot guarantee that a pet will remain completely free of all health concerns. As such, it is imperative for breeders to not only prioritise genetic testing and responsible breeding practices but also to educate prospective pet owners about the potential health risks associated with particular breeds and provide ongoing support and guidance throughout the pet's lifetime.

Health Tests British Bulldogs

This test involves running the dog at a steady trot for three-minutes and assessing their breathing before and after. It is designed to help grade their level of BOAS (Brachycephalic Airway Syndrome), a complex respiratory problem that affects dogs with short skulls, such as the British Bulldog, French Bulldog and Pug. Dogs with moderate or severe BOAS should never be bred.
have had x-rays taken on their breeding dogs to assess the quality of their elbow joints. Dogs with very low ‘elbow scores’ are less likely to develop elbow problems in the future and less likely to pass hereditary elbow problems on to their puppies.
have had x-rays taken on their breeding dogs to assess their ‘hip score’. Dogs with low hip scores have better hips and are less likely to develop problems in the future. Most large and medium sized dog breeds benefit from hip scoring to ensure they are unlikely to pass hereditary hip problems on to their puppies.
Dogs affected by patellar luxation have loose kneecaps that may pop in and out of the knee joint, which can be painful and even require surgery. Having a vet examine breeding dogs for patellar luxation can confirm the dog is not affected, and that their puppies are less likely to develop the condition. Patellar luxation is more common in smaller breeds
Many breeds with screw-tails or long backs are prone to congenital spinal abnormalities such as hemivertebrae or disc calcification. These can cause spinal kinks and instability resulting in a high rate of slipped discs and spinal injury. Breeders can conduct xrays to identify if a breeding dog has a high risk of spinal instability. These dogs should not be bred.
French Bulldogs, Pugs and British Bulldogs have particularly small and narrow (stenotic) nostrils compared to other breeds. The nostrils can be graded on their degree of openness and given a score of ‘open’, ‘mildly stenotic’, ‘moderately stenotic’ and ‘severely stenotic’. Only dogs with open or mildly stenotic nares (nostrils) should be bred to minimise the risk of brachycephalic obstructive airway syndrome in their puppies.
British Bulldogs are known to be high risk for tracheal hypoplasia, where the trachea (windpipe) is very narrow. Some breeders have xrays taken of their breeding dogs to ensure the diameter of their trachea at the level of the thoracic inlet (where the windpipe enters the lungs) is not extremely narrow. Research is still being conducted to determine the significance of these results for puppies.
This is a disease affecting the spinal cord of older dogs, initially causing wobbliness and eventually hindlimb paralysis. It can affect a wide range of breeds. There is now a DNA test that can indicated if a breeding dog is carrying this disease.
It is a hereditary disease that primarily affects certain breeds such as German Shepherds, Boxers, and Pembroke Welsh Corgis, but it can also occur in other breeds.
To date there are no recorded cases in the world in either the British Bulldog or the Chow Chow.
We can test for it so avoid breeding Carrier to Carrier or affected to Carrier.
An eye certificate means the breeder has had their breeding dogs examined by a veterinary ophthalmologist, to confirm they are not affected by any eye conditions which may be passed down genetically to their puppies. It includes breeders who have participated in the Australian Canine Eye Scheme (ACES).
Glaucoma can not be tested for via DNA. The eye certificate is a snap shot at that time.
Hyperuricosuria (HUU) is a genetic disease that causes a build-up of uric acid in the urine, predisposing to painful bladder and kidney stones. It can occur in a range of breeds. There is a DNA test available to identify whether a breeding dog is carrying this disease.
A heart certificate indicates a breeder has had their breeding dogs declared free from common heart conditions which might be passed down genetically to the puppies. This can be done by auscultation or echocardiography with a veterinary cardiologist, or by echocardiography with a GP vet. Common heart conditions include Dilated Cardiomyopathy (DCM) and Myxomatous Mitral Valve Disease (MMVD)

Chow Chow Health Tests

X-rays taken on their breeding dogs to assess the quality of their elbow joints. Dogs with very low ‘elbow scores’ are less likely to develop elbow problems in the future and less likely to pass hereditary elbow problems on to their puppies.
X-rays taken on their breeding dogs to assess their ‘hip score’. Dogs with low hip scores have better hips and are less likely to develop problems in the future. Most large and medium sized dog breeds benefit from hip scoring to ensure they are unlikely to pass hereditary hip problems on to their puppies.
This is a disease affecting the spinal cord of older dogs, initially causing wobbliness and eventually hindlimb paralysis. It can affect a wide range of breeds. There is now a DNA test that can indicated if a breeding dog is carrying this disease.
An eye certificate means the breeder has had their breeding dogs examined by a veterinary ophthalmologist, to confirm they are not affected by any eye conditions which may be passed down genetically to their puppies. It includes breeders who have participated in the Australian Canine Eye Scheme (ACES).
Glaucoma can not be tested for via DNA. The eye certificate is a snap shot at that time.
A heart certificate indicates a breeder has had their breeding dogs declared free from common heart conditions which might be passed down genetically to the puppies. This can be done by auscultation or echocardiography with a veterinary cardiologist, or by echocardiography with a GP vet. Common heart conditions include Dilated Cardiomyopathy (DCM) and Myxomatous Mitral Valve Disease (MMVD).
Osteogenesis Imperfecta (OI), also known as ‘brittle bone disease’, is an inherited disease in both humans and animals, causing bone fragility and fracturing. As it is a genetic disease, breeding parents can be tested to ensure it is not passed onto their puppies.
Dogs affected by patellar luxation have loose kneecaps that may pop in and out of the knee joint, which can be painful and even require surgery. Having a vet examine breeding dogs for patellar luxation can confirm the dog is not affected, and that their puppies are less likely to develop the condition. Patellar luxation is more common in smaller breeds.

Limitations of DNA testing by Orivet Genetic Pet Care

CLARIFICATIONOF GENETIC TESTING

The goal of genetic testing is to provide breeders with relevant information to improve breeding practices in the interest of animal health.However, genetic inheritance is not a simple process, and may be complicated by several factors. Below is some information to help clarify these factors.

1) Some diseases may demonstrate signs of what Geneticists call “genetic heterogeneity”. This is a term to describe an apparently single condition that may be caused by more than one mutation and/or gene

2) It is possible that there exists more than one disease that presents in a similar fashion and segregates in a single breed. These conditions -although phenotypically similar - may be caused by separate mutations and/or genes.

3) It is possible that the disease aecting your breed may be what Geneticists call an “oligogenic disease”. This is a term to describe the existence of additional genes that may modify the action of a dominant gene associated with a disease. These modifier genes may for example give rise to a variable age of onset for a particular condition, or aect the penetrance of a particular mutation such that some animals may never develop the condition.

The range of hereditary diseases continues to increase and we see some that are relatively benign and others that can cause severe and/or fatal disease. Diagnosis of any disease should be based on pedigree history, clinical signs, history (incidence) of the disease and the specific genetic test for the disease. Penetrance of a disease will always vary not only from breed to breed but within a breed, and will vary with dierent diseases. Factors that influence penetrance are genetics, nutrition and environment. Although genetic testing should be a priority for breeders, we strongly recommend that temperament and phenotype also be considered when breeding.