Introduction: The study aimed to clarify the changes in the concentration of inflammatory mediators, proteases, and cartilage degradation biomarkers in the synovial fluid of joints in an equine osteoarthritis model. Material and Methods: Osteoarthritis was induced in eight Mongolian horses by a sterile intra-articular injection of amphotericin B, which was injected into the left carpal joint in a dose of 2 mL (25 mg/mL). The control group comprised five horses which were injected with an equal dose of sterile physiological saline into the left carpal joint. Synovial fluid was obtained at baseline and every week after injection. Test methods were based on ELISA. Results: In the course of the osteoarthritis, the concentration of biomarkers in joint synovial fluid showed an increasing trend. IL-1, IL-6, MMP-9, MMP-13, ADAMTS-5, CS846, GAG, HA, CTX-II, and COMP concentrations sharply increased before the onset of significant symptoms of lameness, whereas TNF-α, MMP-2, and MMP-3 concentrations rose sharply after the occurrence of such symptoms. Conclusion: The results obtained confirm that the concentrations of IL-1, IL-6, MMP-9, MMP-13, ADAMTS-5, CS846, GAG, HA, CTX-II and COMP increase substantially in equine osteoarthritis, which provides a theoretical basis for the rapid diagnosis of the disease.

OBJECTIVE To evaluate the effects of exercise in an underwater treadmill (UWT) on forelimb biomechanics and articular histologic outcomes in horses with experimentally induced osteoarthritis of the middle carpal joint. ANIMALS 16 horses. PROCEDURES An osteochondral fragment was induced arthroscopically (day 0) in 1 middle carpal joint of each horse. Beginning on day 15, horses were assigned to exercise in a UWT or in the UWT without water (simulating controlled hand walking) at the same speed, frequency, and duration. Thoracic and pelvic limb ground reaction forces, thoracic limb kinematics, and electromyographic results for select thoracic limb muscles acting on the carpi were collected on days -7 (baseline), 14, 42, and 70. Weekly evaluations included clinical assessments of lameness, response to carpal joint flexion, and goniometric measurements of thoracic limb articulations. At study conclusion, articular cartilage and synovial membrane from the middle carpal joints was histologically examined. RESULTS Exercise in a UWT significantly reduced synovial membrane inflammation and resulted in significant clinical improvements with regard to symmetric thoracic limb loading, uniform activation patterns of select thoracic limb muscles, and return to baseline values for carpal joint flexion, compared with results for horses with simulated hand walking. CONCLUSIONS AND CLINICAL RELEVANCE Overall improvements in thoracic limb function, joint range of motion, and synovial membrane integrity indicated that exercise in a UWT was a potentially viable therapeutic option for the management of carpal joint osteoarthritis in horses.

Visceral adipose tissue (AT) obtained from surgical waste during routine ovariectomies was used as a source for isolating canine mesenchymal stem cells (MSCs). As determined by cytofluorimetry, passage 2 cells expressed MSC markers CD44 and CD90 and were negative for lineage-specific markers CD34 and CD45. The cells differentiated toward osteogenic, adipogenic, and chondrogenic directions. With therapeutic aims, 30 dogs (39 joints) suffering from elbow dysplasia (ED) and osteoarthritis (OA) were intra-articularly transplanted with allogeneic MSCs suspended in 0.5% hyaluronic acid (HA). A highly significant improvement was achieved without any medication as demonstrated by the degree of lameness during the follow-up period of 1 y. Control arthroscopy of 1 transplanted dog indicated that the cartilage had regenerated. Histological analysis of the cartilage biopsy confirmed that the regenerated cartilage was of hyaline type. These results demonstrate that transplantation of allogeneic adipose tissue-derived mesenchymal stem cells (AT-MSCs) is a novel, noninvasive, and highly effective therapeutic tool in treating canine elbow dysplasia.

OBJECTIVE To determine effects of transforming growth factor (TGF)-β and interleukin (IL)-1β on inflammatory markers in cultured canine chondrocytes to clarify the role of these cytokines in osteoarthritis of dogs. SAMPLE Pooled chondrocytes isolated from the stifle joints of 4 adult dogs. PROCEDURES Chondrocytes were isolated, cultured, and frozen at −80°C. Pooled cells were incubated in medium with or without TGF-β (1 or 10 ng/mL) and subsequently stimulated with IL-1β (10 ng/mL). Concentrations of nitric oxide (NO) and prostaglandin (PG) E were measured in culture supernatants. Gene expression of matrix metalloproteinase (MMP)-3, tissue inhibitor of metalloproteinase (TIMP)-2, inducible NO synthase (iNOS), and cyclooxygenase (COX)-2 was quantified by use of real-time quantitative PCR assays. RESULTS Stimulation with IL-1β increased gene expression of all inflammatory markers, except for TIMP-2. Incubation with TGF-β resulted in a significant decrease in MMP-3 and TIMP-2 mRNA concentrations but had no effect on PGE and NO concentrations. For cells treated with TGF-β followed by IL-1β, concentrations of PGE and NO were lower, compared with concentrations for IL-1β control cells. Furthermore, IL-1β–induced gene expression of iNOS, MMP-3, and COX-2 was downregulated. However, the IL-1β–induced downregulation of TIMP-2 gene expression was partially restored by pretreatment with TGF-β. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that IL-1β increased the expression of inflammatory genes and mediators, and TGF-β largely attenuated the IL-1β–mediated inflammatory response. Therefore, TGF-β might be a novel target for use in the prevention and treatment of cartilage breakdown in dogs with osteoarthritis.

OBJECTIVE To evaluate the effect of bilateral ventriculocordectomy via ventral laryngotomy on laryngeal airway resistance (LAR) in canine cadaver larynges. SAMPLE 6 clinically normal canine cadaver larynges. PROCEDURES LAR was determined for each specimen before (baseline) and after bilateral ventriculocordectomy with the epiglottis open and closed. After ventral laryngotomy was performed, the vocal cords were sharply excised, and the incised mucosal edges were apposed with 4-0 glycomer 631 suture in a simple continuous pattern. The thyroid cartilage was apposed with 3-0 polypropylene suture in a simple continuous pattern. RESULTS With the epiglottis closed, baseline median LAR was 27.6 cm H2O/L/s (range, 21.2 to 30.6 cm H2O/L/s), which did not differ significantly from the median LAR after bilateral ventriculocordectomy (24.7 cm H2O/L/s [range, 20.6 to 27.7 cm H2O/L/s]). With the epiglottis open, baseline median LAR was 7.3 cm H2O/L/s (range, 5.4 to 7.8 cm H2O/L/s), which did not differ significantly from the median LAR after bilateral ventriculocordectomy (7.2 cm H2O/L/s [range, 6.6 to 7.6 cm H2O/L/s]). CONCLUSIONS AND CLINICAL RELEVANCE Bilateral ventriculocordectomy did not affect LAR with an open epiglottis in canine cadaver larynges. Therefore, it may not be an effective treatment for laryngeal paralysis. It also did not affect LAR with a closed epiglottis, which may indicate protection against aspiration pneumonia.