Laurie's Blogs.

Glad you asked!  A recent studies answers that exact question.  Here’s the answer.

A little bit of background

Primary osteoarthritis (OA) is idiopathic and associated with aging and obesity. In dogs, it is more commonly secondary, arising from structural instabilities (e.g., cranial cruciate ligament rupture, hip/elbow dysplasia) or other severe joint diseases (e.g., septic arthritis). Radiographic examination is the most common diagnostic tool for OA, with grading systems typically categorizing severity into four levels: none, mild, moderate, and severe.

OA is the most common joint disease in both human and veterinary medicine. Studies suggest that 38-40% of dogs have radiographic OA, and a significant portion of humans also show radiographic signs of OA (one study found only 13% of the examined persons between 55 and 65 years were free of radiographic visible OA in the hands, hips, knees and spine). Research indicates that male and neutered dogs are at higher risk of developing OA, while in humans, women are more susceptible. There is also an association between gonadectomy and increased risk of OA-related factors, such as hip dysplasia and cranial cruciate ligament rupture, in dogs.

Although OA is degenerative, radiographic signs such as osteophytes, sclerosis, and vascular growth indicate active joint changes. Typical radiographic features of OA include osteophyte and enthesophyte formation, joint effusion, subchondral sclerosis, and soft tissue swelling. This study aims to investigate the prevalence and distribution of radiographic OA in dogs over 8 years old, hypothesizing that most of their joints will show signs of OA.

Materials & Methods

In this retrospective study, records of dogs that had been presented to the veterinary teaching hospital between 2011 and 2019 were used. All dogs aged 8 years or older at the day of presentation were included if one or more of the following radiographs was available: mediolateral projection of the shoulder joint, mediolateral and craniocaudal projection of the elbow joint, ventrodorsal projection of the pelvis, mediolateral and craniocaudal projection of the stifle joints.

Findings?

A total of 1873 dogs of 181 different breeds met the inclusion criteria.  A total of 6296 joints were included, 632 shoulders (10.0%), 1158 elbows (18.4%), 2706 hips (43.0%) and 1800 stifles (28.6%). Of all joints 3756 (59.7%) were free of OA.

Prevalence of OA was 39.2%, 57.4%, 35.9% and 36.4% for the shoulder, elbow, hip and stifle, respectively. There was no correlation between higher grades of OA and weight as well as age, but significantly higher prevalence of OA in heavier groups when grouped for weight. Sex and castration status did not affect presence of OA. 

Bottom line

As most of the examined joints were free of OA, radiographic findings suggestive of OA should not be considered normal in senescent dogs.

Reference

Moritz Roitner, Julius Klever, Sven Reese, Andrea Meyer-Lindenberg. Prevalence of osteoarthritis in the shoulder, elbow, hip and stifle joints of dogs older than 8 years. The Veterinary Journal, Volume 305, June 2024, 106132.