Hip Dysplasia
The Inheritance of Hip Dysplasia
Why is “Genetic” Not a Sufficient Answer?
I often come across posts and discussions where dog owners, after receiving a hip dysplasia diagnosis for their pet, are left confused and searching for answers to the most important question: “But what caused this?”
The most common response from veterinarians is:
“It’s genetic.”
While this statement is partially true, it does not explain the full picture,which is why so many misconceptions and misinformation continue to spread. The inheritance of hip dysplasia is not as straightforward as a classic, single-gene genetic disorder. Oversimplified answers like these only confuse owners further and can hinder both prevention efforts and informed decision-making in breeding and pet ownership.
Genetic Diseases: Single Gene vs. Polygenic
Inheritance
When we say a disease is “genetic,” many people assume it works like:
Progressive Retinal Atrophy (PRA) – A monogenic (single-gene) inherited disease that is directly passed down from parents to offspring. If a puppy inherits the defective gene, it will develop the disease.
Von Willebrand Disease (VWD) – A well-known inherited blood clotting disorder caused by a specific gene mutation, which can be easily detected through DNA testing.
In these cases, the genetic link is clear and direct: if a dog inherits the defective gene, it will be affected; if it does not inherit the gene, it will not be affected.
Hip dysplasia, however, does NOT work this way.
The Inheritance of Hip Dysplasia: Polygenic and Multifactorial
Hip dysplasia is a polygenic and multifactorial disease, which means:
It is not caused by a single gene but rather a combination of multiple genes.
Genetic predisposition alone does not cause hip dysplasia, environmental factors also play a role in determining how severe the condition becomes.
This means that a dog may carry genetic factors that increase the risk of hip dysplasia, but if it experiences optimal environmental conditions, it may remain completely symptom-free. On the other hand, a dog with a lower genetic predisposition can still develop hip dysplasia due to poor environmental conditions.
Why Is the Absence of Hip Dysplasia in Parents Not a Guarantee?
Hip dysplasia is not like a single-gene inherited disease that can be easily eliminated from breeding programs. Due to its polygenic and multifactorial nature, even the most careful selection cannot completely eliminate the disease.
This fact is often overlooked because the claim that a breeding line has been “hip dysplasia-free for multiple generations” serves as an attractive marketing strategy that misleads potential buyers into believing that the puppies can never be affected. This is simply not true.
Many breeders/ future owners assume that if the parents and/or ancestors have been hip dysplasia-free for generations, their offspring will also be unaffected. This is incorrect.
Why?
Recessive Genetic Factors ~> Parents and ancestors may carry recessive genes that do not cause disease on their own, but when combined in a certain way in their offspring, hip dysplasia may develop.
Environment and Epigenetics ~> Genes do not work alone; they are influenced by the environment. An unfavorable environmental factor can activate certain genetic predispositions that might not have caused issues in a different setting.
Polygenic Inheritance ~> Since multiple genes collectively determine hip joint development, even parents with perfect hip scores can pass down genetic combinations that result in hip dysplasia in their offspring.
This is why multi-generational screening reduces risk but NEVER guarantees hip dysplasia-free offspring.
How Can the Risk of Hip Dysplasia Be Reduced?
In our kennel, all breeding dogs are either free from hip dysplasia or, at most, classified as having mild dysplasia, which is considered within breeding ethics acceptable for breeding if paired with a completely free dog.
Additionally, we place great emphasis on early environmental management to ensure the puppies develop in an optimal setting:
Immediately after birth, we place whelping box flooring with corrugated cardboard to provide good grip and prevent slipping. Once they start moving, we switch to soft carpet flooring so that the puppies can crawl easily without their legs slipping out sideways. This early developmental stage is crucial, as excessive sliding and instability can contribute to joint malformations and increase the risk of hip dysplasia later on.
No Guarantees, Only Risk Reduction
Hip dysplasia is not a simple “genetic defect” that can be eliminated through DNA testing. It is a complex, polygenic disorder influenced by both genetic and environmental factors.
Screening and proper breeding practices can reduce the number of severe cases but can never provide a 100% guarantee that a puppy will be free from hip dysplasia.
Both breeders and owners share responsibility in minimizing risk through proper management, nutrition, and controlled movement during the puppy’s early development.
This is why claiming that a breeding line is “hip dysplasia-free for multiple generations” is often used as a marketing shield rather than an absolute truth.
While selective breeding can reduce the risk, the polygenic nature of the disease means that it can still appear unexpectedly, even in well-managed bloodlines.
The image illustrates the different stages of puppy skeletal development, highlighting how much their bones change as they grow. It visually explains how at birth, the skeleton is significantly different, and by two months of age, it has already developed considerably, yet the growth plates remain open, meaning the bones are still forming. This also emphasizes that at this stage, any screening results are not definitive, as the final skeletal structure can still change significantly until full maturity.
Written by Mark Szebasztian Fenyes based on Sources:
Bannasch, D., et al. (2019). Genetic dissection of canine hip dysplasia phenotypes and their underlying genetic determinants. BMC Genomics.
Flückiger, M. (2007). Canine Hip Dysplasia:
Pathogenesis, phenotypic scoring, and genetics.
Veterinary Journal.
Smith, G. K., et al. (1997). Heritability estimates of canine hip dysplasia radiographic traits. American Journal of Veterinary Research.
GROWTH PLATES and why high impact activities like stairs and jumping are bad for young puppies developing joints!
Understanding your puppy’s Growth Plates:
Growth plates, also known as epiphyseal plates, are areas of developing cartilage near the ends of long bones in puppies.
They are responsible for bone growth and gradually harden as a puppy matures. The process of closure is essential for a puppy’s healthy development.
Unfortunately there are alot of things uneducated owners put their puppies thru unknowingly that cause longterm negative effects on their joints.
In Cane Corsos, their growth plates are not fully closed until between 12 to 16 months of age !
What you do in these first 2 years during their early developmental stages has a huge impact on how they turn out as adults!
Let’s discuss how certain activities can set them up for failure later and what you can do to be proactive to set them up for success!
Why High Impact Activities Like Stairs Are Risky:
1. Joint Stress:
The primary concern with stairs is the excessive stress they place on the still-soft growth plates. This stress can disrupt the normal growth process of bones, leading to uneven growth, deformities, and increased susceptibility to joint issues.
2. Specific Joint Vulnerability:
Cane Corsos, like other large and giant breeds, are particularly prone to joint problems due to their size and weight. Their developing joints, such as the hips and elbows, are more susceptible to damage from high-impact activities like climbing stairs.
3. Muscle Development:
Young puppies might not have fully developed muscles to support their joints adequately. Climbing stairs can strain these underdeveloped muscles, which may lead to discomfort and potential injuries.
4. Balance and Coordination:
Puppies are naturally uncoordinated and prone to accidents. Stairs increase the risk of slips and falls, potentially causing traumatic injuries to the growth plates or other body parts.
Being Proactive & Protecting Your Puppy’s Growth Plates:
1. Stair Limitation:
Avoid stairs whenever possible during your Cane Corso’s puppyhood. Carry them up and down stairs or invest in ramps to reduce the impact on their joints.
2. Exercise Management:
Engage your puppy in age-appropriate exercises that don’t involve repetitive or high-impact movements.
Short, controlled walks on flat surfaces are preferable.
3. Balanced Diet:
Ensure your puppy receives a high-quality, breed-specific, and age-appropriate diet rich in nutrients that are formulated especially for giant breed puppies. Diet is everything!
4. Regular Check-ups:
Regular veterinary visits are essential to monitor your puppy’s growth and address any emerging issues promptly. Your vet can provide guidance on your puppy’s specific needs. Make sure your vet understands giant breed specific requirements. (*Not all vets do!)
5. Supplements:
Discuss with your veterinarian the use of joint supplements containing ingredients like glucosamine, chondroitin, and krill oil with omega-3 fatty acids.
These supplements can support joint health and reduce the risk of future problems.
6. Understanding the negative effects of early spay/ neuter has on dogs over all health. Early effects meaning prior to 12 months of age!.