Osteoarthritis in Dogs Part I: Causes, Signs, Prevention & Diagnosis

Osteoarthritis – also known as degenerative joint disease (DJD) – is the most common arthritic condition in dogs, afflicting approximately 20% of dogs. Of course, those are the dogs diagnosed, so the number could be much higher.

Osteoarthritis is the result of underlying or triggering condition or event, or the intricate interplay of some condition such as trauma, lifestyle, stressor, environmental exposure, dietary and drug sensitivity, and/or genetic predisposition.

Before we delve into those, let’s have an anatomy lesson.

What is osteoarthritis?

When we think of osteoarthritis, we are reminded of “The Skeleton Dance” song that has lyrics such as “The leg bone is connected to the knee bone, the knee bone is connected to the thigh bone.” Well, what important feature is missing from the song that is connecting all of these bones? Joints.

Synovial fluid helps lubricate the joint to help everything move smoothly. As an added layer of protection, there is cartilage between bones as a liner or cushion. This cartilage can become damaged and begin to disintegrate, which results in inflammation of the synovial fluid and osteoarthritis.

Many of us think of osteoarthritis in the hips or the knees. That makes sense as those are the places humans generally develop clinical symptoms/signs. However, we need to remember that osteoarthritis could impair shoulders or any other joint for that matter.

What are the causes of osteoarthritis?

Osteoarthritis in a dog is usually multifactorial. Here are some possibilities in no particular order:

#1. Genetic background and family predisposition that can affect body and joint conformation

#2. Muscle weakness

#3. Obesity or overweight

#4. Abnormal joint development (e.g. canine hip dysplasia, elbow dysplasia, luxating patellas)

#5. Joint laxity

#6. Low activity history

#7. Injury

#8. Orthopedic surgery

#9. Nutrition

#10. Hypothyroidism and autoimmune thyroiditis

#11. Certain drugs, toxins, infectious exposures

#12. Long-term use of steroids

#13. Immune-mediated diseases (e.g. Systemic lupus erythematosus , SLE; Rheumatoid arthritis, RA)

Signs of Osteoarthritis

Think about when you wake up in the morning and you can feel the difference between sore joints and sore muscles. After a big day of exercise, it is more than likely your muscles – and maybe your joints. If you had not worked out the day before, it is probably your joints. For dogs, this might be a good gauge that your dog may have osteoarthritis, but you will need to relay that to your veterinarian. Dogs will typically exhibit the following signs: difficulty getting up and down, walking stiffly, lameness, reluctance to jump or use stairs, limping, or even aggression.


It is interesting that when we read some of the general articles about osteoarthritis in dogs, they skirt around using the word “genetics”. They describe body conformation in addition to trauma and lifestyle. We completely understand why they choose to avoid the words “genetics” or “epigenetics” (the study of how behaviors and environment can cause changes that affect the way genes work). We believe it is because researchers have only really started pinpointing the genes associated with causing osteoarthritis, and that we know how relatively easy it is to try to delay the disease with lifestyle and other choices.

On the flip side, there are many convinced researchers who state that we often overlook the genetic and growth factors. They say that osteoarthritis probably starts at an earlier age, but that the signs usually do not appear until later in life.

For instance, canine hip dysplasia (a disease that can cause osteoarthritis) varies amongst breeds, but up to 75% in Golden Retrievers and Rottweilers can develop it. Indeed, heritability ranges from 20%-60%. Again, we are in the midst of discovering the genes associated with it.

Legg-Calvé-Perthes disease affects the hip joints predominantly in small-breed dogs such as Yorkshire Terriers, Maltese, Miniature Poodles and Chihuahuas. Osteochondrosis dissecans (OCD) is found in the shoulder of large or giant breeds particularly the Great Dane and Old English Sheepdog. Again, we know there is a genetic component.

Rupturing of the cranial cruciate ligament (CCL) – the canine equivalent of the human knee ACL – drives home the reminder that lifestyle factors such as activity level (which has a direct effect on muscle strength) and obesity play a huge role in recovery and osteoarthritis outcome. Yes, CCL ruptures commonly affect both small and large breeds including: West Highland White Terriers, Staffordshire Bull Terriers, Golden Retrievers, Labrador Retrievers, Rottweilers and others. Yes, we know the genes possibly causing CCL ruptures, but the interactions are definitely more complex than one would imagine.

Obesity Connection

Even though a genetic factor is documented or suspected in some breeds, it does not mean that other breeds without the genetic factor cannot develop osteoarthritis as well. As we stated earlier, osteoarthritis is multifactorial. So, companion dog parents should reduce the severity and outcome of the disease with proper weight and activity management. This is one thing we can control.

Think about it this way. Do you know anybody with “knock knees”? Obesity can contribute to genu valguma (the medical term for knock knees), which causes a knee to tilt inward because it has an incorrect alignment around the knee. Over time, the imbalance of force it places on the knees can cause pain, joint damage and early onset knee arthritis.

The same can ring true for companion dogs. Maybe they don’t develop knock knees per se, but they can have abnormal development of joints caused by obesity, accelerated growth, and/or genetics that leads to osteoarthritis.

Case in point, a study published in 2013 observed gait at a trot of 8 lean and 8 obese adult dogs that were recruited from dog parks and veterinary clinics. The researchers excluded small breeds, giant breeds, and chondrodystrophic breeds (Dachshunds, Corgis, Bassett Hounds, etc.). They made a point of only allowing dogs that had no known history of orthopedic injury, osteoarthritis, or lameness as determined on the basis of patient history and physical and orthopedic examinations.

The authors concluded, “Greater range-of-motion detected during the stance phase and greater ground reaction forces in the gait of obese dogs, compared with lean dogs, may cause greater compressive forces within joints and could influence the development of osteoarthritis.”


Several retrospective studies have compared the prevalence of obesity/overweight in dogs that were intact versus those that were spayed/neutered. The majority have found that neutered/spayed dogs were more prone to obesity – particularly neutered males.

In 2019, Simpson et al. added the element of CCL injury in Golden Retrievers. Remember, Goldens do have a genetic factor for CCL injury.

They concluded, “This study presents prospectively acquired data demonstrating that gonadectomy (neutered) is a risk factor for both overweight/obesity and chronic non-traumatic orthopedic injuries in a prospective cohort of Golden Retrievers. Our data suggest that gonadectomy at any age is a risk factor for overweight or obesity, but delaying gonadectomy until dogs are at least 6–12 months of age may help to decrease the risk for orthopedic injury.”

While we do not doubt their conclusions, we suggest that other factors such as caloric intake should be addressed as well. We are pleased the authors did include physical activity and determined that low physical activity was associated with a higher body condition score (that means excess fat). However, they did not factor in caloric feeding per day. Intact dogs are supposed to eat more than their gonadectomy counterparts. So, the researchers did not determine if calories were adjusted downward due to the absence of the hormones. We think this should be the next step in research.

Nutraceuticals for Prevention

The study results are mixed as to the benefits and need for omega-3 fatty acids, glucosamine and chondroitin. Currently, there is no evidence of long-term harm in providing companion dogs with these joint supplements, if given at the appropriate dosage.

One of the inherent misconceptions is that we should administer these to dogs that are diagnosed with osteoarthritis. While we can give them, they are premised on being preventative and given before the onset of symptoms.

Regarding glucosamine and chondroitin, they may slow cartilage degeneration, contribute to cartilage repair, reduce inflammation of the joints, and improve elasticity.

Omega-3 fatty acids and green-lipped mussel extract can reduce inflammation due to osteoarthritis.

Be advised that the helpful effects are not usually noticeable for 4-8 weeks. As well, if you are feeding a food that is already high in these ingredients, you should not add additional supplementation.

Diagnosing Osteoarthritis

Initially, a physical examination, routine blood and perhaps urine tests, and clinical and family history are performed by the veterinarian. Additional tests may include X-rays, MRIs or CT scans.


In summary, genetics and their predisposition are important factors. Hormones are a factor. Lifestyle choices are a factor. What can we control at this point in time to delay, mitigate or prevent the onset of osteoarthritis/DJD disease? Lifestyle with plenty of activity and proper feeding.

In our next post, we will discuss additional treatment options for osteoarthritic dogs. Even if your companion dog does not have a diagnosis, you may still find the information interesting!


Anderson, Katharine L., et al. “Prevalence, Duration and Risk Factors for Appendicular Osteoarthritis in a UK Dog Population under Primary Veterinary Care.” Scientific Reports, vol. 8, no. 1, 4 Apr. 2018, https://doi.org/10.1038/s41598-018-23940-z

Binversie, Emily E., et al. “Across-Breed Genetic Investigation of Canine Hip Dysplasia, Elbow Dysplasia, and Anterior Cruciate Ligament Rupture Using Whole-Genome Sequencing.” Frontiers in Genetics, vol. 13, 2 Dec. 2022, https://doi.org/10.3389/fgene.2022.913354

Brady, Robert B., et al. “Evaluation of Gait-Related Variables in Lean and Obese Dogs at a Trot.” American Journal of Veterinary Research, vol. 74, no. 5, 1 May 2013, pp. 757–762, https://doi.org/10.2460/ajvr.74.5.757

Courcier, E. A., et al. “An Epidemiological Study of Environmental Factors Associated with Canine Obesity.” Journal of Small Animal Practice, vol. 51, no. 7, 2010, pp. 362–367, https://doi.org/10.1111/j.1748-5827.2010.00933.x

Lefebvre, Sandra L., et al. “Effect of Age at Gonadectomy on the Probability of Dogs Becoming Overweight.” Journal of the American Veterinary Medical Association, vol. 243, no. 2, 15 July 2013, pp. 236–243, https://doi.org/10.2460/javma.243.2.236

Marcellin-Little, Denis. Sorting Facts from Fiction: Canine Osteoarthritis Myths. DVM 360, 12 June 2017, https://www.dvm360.com/view/sorting-facts-fiction-canine-osteoarthritis-myths

Meeson, Richard L., et al. “Spontaneous Dog Osteoarthritis — a One Medicine Vision.” Nature Reviews Rheumatology, vol. 15, no. 5, 5 Apr. 2019, pp. 273–287, https://doi.org/10.1038/s41584-019-0202-1

Rice, Sarah J., et al. “Interplay between Genetics and Epigenetics in Osteoarthritis.” Nature Reviews Rheumatology, vol. 16, no. 5, 9 Apr. 2020, pp. 268–281, https://doi.org/10.1038/s41584-020-0407-3

Simpson, Melissa, et al. “Age at Gonadectomy and Risk of Overweight/Obesity and Orthopedic Injury in a Cohort of Golden Retrievers.” PLOS ONE, vol. 14, no. 7, 17 July 2019, https://doi.org/10.1371/journal.pone.0209131

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