The influence of IL-1 and C-reactive protein levels in synovial fluid of companion dogs with bilateral hip osteoarthritis on various clinical disease parameters

Abstract

OBJECTIVE To evaluate IL-1 and C-reactive protein (CRP) levels in the synovial fluid in dogs with bilateral hip osteoarthritis and their relation to animals’ clinical, radiographic, and thermographic disease signs. SAMPLE 100 joints from police working dogs. PROCEDURES Synovial fluid, IL-1, and CRP levels, weight distribution, joint range of motion, thigh girth, digital thermography, and radiographic signs of the joints were recorded. Data from 4 clinical metrology instruments (CMIs) were collected. Results were compared by age, sex, and Orthopedic Foundation for Animals hip scores with the independent samples t test, ANOVA, and Pearson correlation coefficient (P < .05). RESULTS The sample included 100 pelvic limbs, equally distributed between left and right pelvic limbs 30 males and 20 females, with a mean age of 6.5 ± 2.4 years and body weight of 26.7 ± 5.2 kg. IL-1 levels, particularly above 200 pg/mL, may be related to the development of caudolateral curvilinear osteophyte, which then expresses a toll on the patient’s levels of pain and activity. It was unclear if the CRP levels were a consequence of inflammatory activity within the joint or a reflection of a better prognosis. Increasing body weight was related to worse CMI scores. CLINICAL RELEVANCE We described the relation of IL-1 and CRP synovial concentration levels with several clinical signs, diagnostic imaging, laboratory findings, and CMI results of animals with osteoarthritis. Further studies are required to determine the interest of each parameter for the prognosis and treatment monitoring.