Osteoarthritis (OA) is a common degenerative joint disease in dogs, characterized by progressive cartilage deterioration, chronic pain, and reduced mobility. This prospective, cross-sectional study aimed to determine the prevalence of osteoarthritis-related pain and identify potential risk factors through owner-reported assessments. The study involved a population of 259 dogs of various breeds, ages, and sexes. Owners completed validated clinical metrology instruments, including the Canine Brief Pain Inventory (CBPI), Helsinki Chronic Pain Index (HCPI), and Liverpool Osteoarthritis in Dogs (LOAD), to evaluate the severity of pain and its impact on the dogs' quality of life. The results indicated a significant prevalence of chronic pain among the study population, with age and body weight identified as key predictors of OA severity. Specifically, older dogs and those with higher body weight exhibited higher pain scores across all instruments. Furthermore, certain environmental factors, such as exercise levels and housing conditions, were found to influence the progression of the disease. These findings emphasize the importance of early detection and the role of owners in identifying subtle signs of OA-related pain. Utilizing standardized pain assessment tools can aid in the timely diagnosis and management of canine osteoarthritis, ultimately improving the health and welfare of affected dogs.
Osteoarthritis (OA) is a significant concern in veterinary medicine, representing one of the most prevalent degenerative joint diseases in dogs. Characterized by the progressive degeneration of articular cartilage, this condition is accompanied by inflammation processes resulting in chronic pain, reduced mobility, and compromised quality of life (
The etiology of OA in dogs is complex and multifactorial. Key risk factors include age, weight, body condition score (BCS), genetics, and prior joint trauma (
While key risk factors such as age and obesity are well-documented, their prevalence and impact within different canine populations remain inadequately explored. Much of the large-scale epidemiological research on canine OA originates from specific geographic regions like the UK and the US, where the canine populations are predominantly neutered (
This study aimed to address these gaps by providing a comprehensive assessment of OA in a previously under-documented canine population in North Macedonia, incorporating three validated pain assessment tools: Liverpool Osteoarthritis in Dogs (LOAD), Helsinki Chronic Pain Index (HCPI), and Canine Brief Pain Inventory (CBPI). Each questionnaire included a pain scale to evaluate the intensity of pain experienced by the dogs. Additionally, the study sought to identify key risk factors associated with OA development and provide insight into the diagnosis and management of OA cases in clinical practice.
This prospective, cross-sectional study was based on collected data through an online survey completed by 259 dog owners from North Macedonia. All participating dog owners provided informed consent by voluntarily completing an online survey that contained detailed information regarding the study's purpose, data collection methods, and intended scientific applications. A full version of the questionnaire used in this study is available at:
The questionnaire was organized into four sections: (1) demographic data, including sex, age, breed, body weight, and neuter status; (2) environmental and lifestyle factors, such as movement restrictions, access to slippery surfaces, and available walking space; (3) owner-perceived mobility issues and pain-related clinical signs; and (4) three validated pain and mobility assessment tools. Owners completed the questionnaires based on their routine observations of the dog’s behavior, and the resulting scores were used to identify dogs suspected of having OA for further clinical evaluation.
Pain and mobility were assessed using three validated owner-completed questionnaires: the Canine Brief Pain Inventory (CBPI), the Helsinki Chronic Pain Index (HCPI), and the Liverpool Osteoarthritis in Dogs (LOAD). LOAD includes 13 items scored from 0 to 4, producing a total score between 0 and 52; HCPI includes 11 items scored from 0 to 4, for a range of 0 to 44; and CBPI consists of 10 items scored from 0 to 10. For analytical purposes, a mean index value was calculated for each dog by averaging their responses per questionnaire. This resulted in a final score range of 0–10 for CBPI, and 0–4 for both HCPI and LOAD. These index values were treated as continuous variables in the statistical analysis, with higher scores indicating more severe pain or mobility impairment. A subset of 56 dogs (22%) that exhibited pain across all three assessments were selected for further clinical evaluation. Dogs were excluded from the study if they had received non-steroidal anti-inflammatory drugs (NSAIDs) within the previous two weeks, glucocorticoids or opioids within the last four weeks, or if they had any clinically significant medical conditions that required daily medication. Owners of the selected dogs were contacted by phone to obtain additional information and consent for further evaluation.
The clinical evaluation included a detailed history of the dog’s medical background, a physical examination, and neurological and orthopedic assessments to rule out other causes of pain. Gait analysis was performed using video recordings to support clinical observation of movement abnormalities. Body condition scores (BCS) were recorded using a 9-point scale. The BCS categories were: 1–3 (underweight), 4–5 (ideal), and 6–9 (overweight to obese) (
The demographic data were classified into predefined categories. Dogs were divided into five age groups: young (≤3 years), junior (3–5 years), adult (5–9 years), mature (9–13 years), and geriatric (≥13 years). Breeds were categorized as mixed breed or purebred, and sex was classified as male or female. Based on body weight, dogs were grouped into small (1–10 kg), medium (11–26 kg), large (27–45 kg), and giant (≥46 kg) breeds. Neuter status was classified as intact, castrated (males), or spayed (females). Additionally, the questionnaire included owner-reported perceptions of pain, exposure to slippery surfaces, and restrictions in walking space.
All statistical analyses were conducted using R software (version 4.4.2; R Foundation for Statistical Computing, Vienna, Austria) and Microsoft Excel. Descriptive statistics were used to summarize demographic characteristics, pain index scores, and OA severity levels. Chi-Square tests were applied to assess associations between OA severity and categorical variables, such as age, weight category, and BCS. Logistic regression analysis was performed to identify predictors of moderate/severe OA, with results presented as Odds Ratios (OR) and 95% Confidence Intervals (CI). Standard Error of the Mean (SEM) was calculated for pain index scores to assess variability, and p-values<0.05 were considered statistically significant.
Grammarly platform (
The study included 259 dogs, with demographic data summarized in Table 1, compiled from completed owner questionnaires. The majority of dogs involved in this study were male (61.8%). Most dogs were between 3 and 9 years old, with the largest proportion (32.0%) falling within the 5–9 years category. Regarding weight, dogs were evenly distributed across the three categories: small (35.5%), medium (27.0%), and large (30.1%), with a smaller proportion (7.3%) classified as giant breeds. Most dogs were purebred (80.7%) and intact (67.2%), while 19.3% were mixed breed and 32.8% were neutered. Body condition assessment revealed that overweight dogs were the most prevalent (61.0%), while a smaller proportion of the dogs had ideal weight (38.6%) or were underweight (0.4%).
Demographic and clinical characteristics of the study population (n=259), including sex, age distribution, body weight, pain assessment scores (CBPI, HCPI, LOAD), movement restrictions, and environmental factors. Data are presented as counts (n), percentages (%), and 95% confidence intervals (CI) for each category
| Category | Details | n | % | 95% CI |
|---|---|---|---|---|
|
|
Male | 160 | 61.8% (160/259) | 55.9%–67.7% |
| Female | 99 | 38.2% (99/259) | 32.3%–44.1% | |
|
|
<3 years old | 80 | 30.9% (80/259) | 25.3%–36.5% |
| 3–5 years old | 54 | 20.8% (54/259) | 15.9%–25.7% | |
| 5–9 years old | 83 | 32.0% (83/259) | 26.3%–37.7% | |
| 9–13 years old | 33 | 12.7% (33/259) | 8.7%–16.7% | |
| Geriatric (>13 years) | 9 | 3.5% (9/259) | 1.2%–5.8% | |
|
|
Pure breed | 209 | 80.6% (209/259) | 75.9%–85.5% |
| Mixed breed | 50 | 19.4% (50/259) | 14.5%–24.1% | |
|
|
Neutered | 85 | 32.8% (85/259) | 27.1%–38.5% |
| Intact | 174 | 67.2% (174/259) | 61.4%–72.9% | |
|
|
Small | 92 | 35.5% (92/259) | 29.7%–41.3% |
| Medium | 70 | 27.0% (70/259) | 21.6%–32.4% | |
| Large | 78 | 30.1% (78/259) | 24.5%–35.7% | |
| Giant | 19 | 7.3% (19/259) | 4.2%–10.5% | |
|
|
No Pain | 156 | 60.2% (156/259) | 54.3%–66.2% |
| Mild | 57 | 22.0% (57/259) | 17.0%–27.1% | |
| Moderate | 10 | 3.9% (10/259) | 1.5%–6.2% | |
| Severe | 36 | 13.9% (36/259) | 9.7%–18.1% | |
|
|
Healthy | 162 | 62.5% (162/259) | 56.7%–68.4% |
| Chronic pain | 97 | 37.5% (97/259) | 31.6%–43.3% | |
|
|
Mild | 118 | 45.6% (118/259) | 39.5%–51.6% |
| Moderate | 74 | 28.6% (74/259) | 23.1%–34.1% | |
| Severe | 32 | 12.4% (32/259) | 8.3%–16.4% | |
| Extreme | 35 | 13.5% (35/259) | 9.4%–17.7% | |
|
|
Free | 209 | 80.7% (209/259) | 75.9%–85.5% |
| Restricted | 50 | 19.3% (50/259) | 14.5%–24.1% | |
|
|
Yes | 169 | 65.3% (169/259) | 59.5%–71.1% |
| No | 90 | 34.7% (90/259) | 28.9%–40.5% | |
|
|
Exam done | 56 | 21.6% (56/259) | 16.6%–26.6% |
| Not done | 203 | 78.4% (203/259) | 73.4%–83.4% | |
|
|
Single Joint | 14 | 5.4% (14/259) | 2.7%–8.2% |
| Multiple Joints | 42 | 16.2% (42/259) | 11.7%–20.7% | |
|
|
Limping (Severe) | 21 | 8.1% (21/259) | 4.8%–11.4% |
| Extreme weight shifting | 13 | 5.0% (13/259) | 2.4%–7.7% | |
| Moderate limping | 11 | 4.2% (11/259) | 1.8%–6.7% | |
| Moderate normal limp | 5 | 1.9% (5/259) | 0.3%–3.6% | |
|
|
Overweight to obese | 158 | 61.0% (158/259) | 55.1%–66.9% |
| Ideal | 100 | 38.6% (100/259) | 32.7%–44.5% | |
| Underweight | 1 | 0.4% (1/259) | 0%–1.2% |
The mobility evaluation revealed that while most dogs (80.7%) had free movement, a smaller proportion (19.3%) experienced some form of restriction. Gait abnormalities were detected in 21.2% of dogs, most commonly presenting as limping, extreme weight shifting, or moderate asymmetry in movement. Joint involvement analysis indicated that 16.2% of dogs had multiple joints affected, while 5.4% had a single joint affected.
The pain assessments using the CBPI questionnaire showed that 39.8% of the dogs had mild to severe pain. Similarly, 37.5% of the dogs were classified as having chronic pain in the HCPI questionnaire. LOAD questionnaire indicated that 45.6% had mild pain, whereas 39.7% had moderate to extreme pain.
The dogs with high pain scores on the questionnaires were called for further evaluation. Fifty-six dogs (22%) underwent clinical examination, confirming OA in all cases. Gait analysis showed that while 22% of dogs exhibited visible lameness, many owners did not recognize these movement abnormalities. Additionally, owner-reported mobility issues (28.6%) did not always correlate with observed clinical signs.
Lateral radiograph of the stifle joint in a dog with advanced osteoarthritis. Marked periarticular osteophyte formation, joint space narrowing, and subchondral bone sclerosis are visible, consistent with chronic degenerative joint disease
The findings from this study identify excess body weight and, more specifically, a high body condition score (BCS) as powerful predictors of OA severity and associated chronic pain. Our analysis revealed that BCS was the single strongest predictor of moderate to severe OA. Body weight and obesity have been strongly associated with chronic pain severity in dogs, impacting the progression and clinical signs of OA. Research indicates that larger breeds, particularly large and giant-sized dogs, exhibit significantly higher pain scores when assessed using various pain assessment tools such as the CBPI and LOAD questionnaire (
Current veterinary recommendations highlight the need for maintaining a healthy weight to prevent increased mechanical stress on joints, further supporting the need for a proactive approach to managing canine obesity (
Association between chronic pain and weight category. Different lowercase letters (a, b, c) above the bars indicate statistically significant differences between weight categories (p<0.05)
Association between chronic pain and BCS. Different lowercase letters (a, b, c) above the bars indicate statistically significant differences between groups (p<0.05); the asterisk (*) denotes the underweight category was excluded from comparative subgroup analysis due to insufficient sample size (n=1)
Predictor variables for OA. The horizontal lines show the 95% confidence intervals
In this study, age has been identified as the significant risk factor for chronic pain and the progression of osteoarthritis (OA) in dogs, as indicated in CBPI and HCPI scores. Dogs aged nine years and older demonstrated increasing pain levels, consistent with literature suggesting age-related joint degeneration and cumulative mechanical stress as contributors to OA development (
The phenomenon underscores the need for observant monitoring of older dogs, as they are more susceptible to complications of OA, which include chronic pain and decreased mobility (
Associations between different age groups and chronic pain. Different lowercase letters (a, b, c) above the bars indicate statistically significant differences between age groups (p<0.05); same letters (a) indicate non-significant difference (p>0.05)
An important discrepancy exists between owner-reported pain signs in dogs and objective clinical findings regarding OA. Our study revealed that while 28.6% of dog owners reported mobility issues, clinical gait analyses confirmed lameness in only 22% of cases, with subtle movement abnormalities often remaining unnoticed by dog owners. This suggests that many owners may not be familiar with the early signs of OA, such as reluctance to jump, stiffness following rest, or changes in behavior, potentially leading to delayed intervention and treatment (
Research consistently highlights that pet owners commonly attribute mobility problems to aging rather than specific conditions like OA, which often result in significant underdiagnosis and insufficient pain management in affected dogs (
Educating pet owners about the clinical signs of OA is crucial for promoting early detection. Improved owner awareness can facilitate timely veterinary visits and interventions, which are pivotal in managing the progression of the disease (
For veterinary practitioners, our results suggest that implementing a multimodal approach, where we combine weight management, owner education, and regular clinical assessments, can significantly improve outcomes for dogs with OA. Early intervention, particularly in at-risk populations such as older dogs and overweight individuals, can help mitigate the progression of this condition and improve the quality of life for the affected animals.
This study confirms that age, weight, and obesity are significant contributing factors to the development of OA in dogs, reinforcing the importance of early detection, weight management, and comprehensive clinical assessments for effective OA management. Our findings highlight that Body Condition Score serves as a powerful predictor of pain severity, suggesting that weight management should be a key component of OA prevention and treatment strategies. The observed gap between owner-reported signs and clinical findings highlights the need for enhanced owner education about the subtle signs of OA and the importance of regular veterinary assessment. This discrepancy underscores the value of using validated pain assessment tools to objectively evaluate pain levels and mobility limitations in dogs with OA.
The research was supported by the Faculty of Veterinary Medicine in Skopje and the University Veterinary Hospital at the Faculty of Veterinary Medicine in Skopje.
The authors declare that they have no financial or non-financial conflict of interest regarding authorship and publication of this article.
JV conceived the study and wrote the manuscript. KI supervised the clinical examination and the questionnaires and contributed to interpretating the results. BC was included in analyzing the questionnaires and interpreting the results. PT, BD, DB and FT were included in the clinical examinations of the patients and interpreted the results. MN and IS participated in reviewing and editing the manuscript. AC was involved in manuscript writing and reviewing. Each author approved the final version of the manuscript to be published and agreed to be accountable for all aspects of the work.