Incidental osteoarthritis: risk factors, prevalence and clinical evidence in rabbits

The objective of this retrospective cohort study was to evaluate the prevalence, risk factors and level of clinically apparent disease associated with appendicular osteoarthritis in a population of rabbits under veterinary care. Computed tomography reports of 311 rabbits taken for any reason over a 4-year period were evaluated for recorded evidence of appendicular osteoarthritis and the joint(s) affected. Risk factors including age, weight, body condition, breed, sex and neuter status were investigated. In rabbits with evidence of osteoarthritis, clinical notes were examined to evaluate if the condition was clinically apparent. Out of 311 computed tomography reports, 61 described evidence of osteoarthritis (19.6%). The most common joints affected were the elbow and stifle. No significant relationship between sex, body condition and neuter status in males and presence of osteoarthritis was found. A statistically significant relationship between greater age, greater weight and neuter status in females and the presence of osteoarthritis was found. Only 9 out of 61 (14.8%) of the rabbits with computed tomography evidence of osteoarthritis had clinical signs of osteoarthritis recorded in the clinical notes. Following the results of this study, it may be concluded that greater age and weight, as well as female neuter status, are related to increased risk of appendicular osteoarthritis in rabbits, but changes on imaging may relate poorly to clinically apparent disease.