Gelatinase activity in synovial fluid and synovium obtained from healthy and osteoarthritic joints of dogs

OBJECTIVE: To determine matrix metalloproteinase (MMP) activity in synovial fluid (SF) obtained from the joints of dogs with degenerative joint disease (DJD) secondary to various underlying conditions. SAMPLE POPULATION: 35 samples of SF obtained from 18 clinically normal (control) dogs and 34 samples of SF obtained from 17 dogs with DJD; dogs with DJD were from 2 populations (client-owned dogs and research dogs that had DJD secondary to the lysosomal storage disease mucopolysaccharidosis VII). PROCEDURE: MMP activity in samples of SF was semiquantitatively examined by use of gelatin or casein zymography. Western blot analysis was performed by use of antibodies for MMP-2 and MMP-9. In addition, in situ MMP activity was observed in sections of synovial membrane obtained from healthy and osteoarthritic joints. RESULTS: Samples of SF from osteoarthritic joints had higher MMP-2 activity and dramatically increased MMP-9 activity, compared with values for healthy joints. Substrate-overlay analyses indicated minimal gelatin-degrading activity in synoviocytes obtained from control dogs, whereas greater activity was seen in osteoarthritic synoviocytes, with additional activity in the underlying tissue. CONCLUSIONS AND CLINICAL RELEVANCE: Higher MMP-2 activity and dramatic increases in MMP-9 activity were associated with the osteoarthritic state, even though MMP-2 activity was detected in healthy joints. This study expands information on MMP production in SF of osteoarthritic joints in other species and documents the similarity of MMP activity patterns regardless of the cause of DJD.     

Concentrations of cartilage oligomeric matrix protein in dogs with naturally developing and experimentally induced arthropathy

OBJECTIVE: To assay concentrations of cartilage oligomeric matrix protein (COMP) in canine sera and synovial fluid (SF), to compare COMP concentrations in clinically normal dogs and dogs with joint disease, and to analyze changes in COMP concentrations in dogs with experimentally induced acute synovitis. ANIMALS: 69 control dogs without joint disease, 23 dogs with naturally occurring aseptic arthropathy, and 6 dogs with experimentally induced synovitis. PROCEDURE: Serum (n = 69) and SF (36) were obtained from control dogs. Samples of serum (n = 23) and SF (13) were obtained from dogs with naturally occurring aseptic arthropathy with or without radiographic features of osteoarthritis (OA). Serum and SF were obtained before and 1, 2, 3, and 7 days after induction of synovitis. The COMP concentrations were determined by use of an inhibition ELISA that had canine cartilage COMP and monoclonal antibody against human COMP. RESULTS: Concentrations of COMP in serum and SF of control dogs were 31.3+/-15.3 and 298.7+/-124.7 microg/ml, respectively. In naturally occurring OA, COMP concentrations in serum (44.9+/-177 microg/ml) and SF (401.7+/-74.3 microg/ml) were significantly higher than corresponding concentrations in control dogs. The COMP concentration in SF peaked 24 and 48 hours after induction of synovitis, whereas concentration in serum peaked on day 3. CONCLUSIONS AND CLINICAL RELEVANCE: These results supported the hypothesis that COMP concentration in serum and SF of dogs may be altered after cartilage degradation or synovitis. Measurement of COMP concentrations can be useful when differentiating arthropathies in dogs.     

Physiological Concentrations of Acute-Phase Proteins and Immunoglobulins in Equine Synovial Fluid

Synovial fluid (SF) is capable of reflecting infectious, immunological, or inflammatory joint conditions in horses by altering its composition and appearance. Although plasma and SF compositions are quantitatively different, this latter compartment reflects changes in plasma macromolecules. Therefore, changes in serum immunoglobulin protein concentrations tend also to alter intracapsular levels. Therefore, it is necessary to know the physiological concentrations of proteins present in SF. The aim of this study was to determine the levels of total protein, albumin, transferrin, haptoglobin, α1-acid glycoprotein, ceruloplasmin, and immunoglobulins A and G in SF of six healthy horses. The synovial proteinogram was obtained by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The SF proteins reached a maximum of 25% of serum concentrations, varying inversely with molecular weight of the protein, except for the ceruloplasmin.     

Glycosaminoglycans in horses with osteoarthritis

Horse articular cartilage glycosaminoglycans (GAGs) were measured in synovial fluids from 48 joints affected with osteoarthritis (OA), 22 normal joints, four joints with osteochondritis, three joints with traumatic arthritis and seven joints infected with bacteria. Serum and urine from individual horses were also examined for the presence of GAGs. High levels of GAGs were found in synovial fluids (SF) from horses with OA. In each case, the level was higher in the synovial fluid than in the serum or urine from the same horse. Horses with OA showed high GAG levels in SF, serum and urine compared to horses with normal and infected joints. High levels were also found in horses with osteochondritis and traumatic arthritis. Levels of synovial fluid GAG reflect cartilage destruction in arthritis and may be useful for monitoring disease progression in the equine species.     

Plasma and synovial fluid endothelin-1 and nitric oxide concentrations in horses with and without joint disease

OBJECTIVE: To compare plasma and synovial fluid endothelin-1 (ET-1) and nitric oxide (NO) concentrations in clinically normal horses and horses with joint disease. ANIMALS: 36 horses with joint disease, and 15 horses without joint disease. PROCEDURE: Horses with joint disease were assigned to 1 of the 3 groups (ie, synovitis, degenerative joint disease [DJD], or joint sepsis groups) on the basis of findings on clinical and radiographic examination and synovial fluid analysis. Endothelin-1 and NO concentrations were measured in plasma from blood samples, collected from the jugular vein and ipsilateral cephalic or saphenous vein of the limb with an affected or unaffected joint, as well as in synovial fluid samples obtained via arthrocentesis from the involved joint. RESULTS: Plasma ET-1 concentrations between affected and unaffected groups were not significantly different. Median concentration and concentration range of ET-1 in synovial fluid obtained from the joint sepsis group (35.830 pg/mL, 7926 to 86.614 pg/mL; n = 7) were significantly greater than values from the synovitis (17.531 pg/mL, 0.01 to 46.908 pg/mL; 18), DJD (22.858 pg/mL, 0.01 to 49.990 pg/mL; 10), and unaffected (10.547 pg/mL, 0.01 to 35.927 pg/mL; 10) groups. Plasma and synovial fluid NO concentrations between affected and unaffected groups were not significantly different. CONCLUSIONS AND CLINICAL RELEVANCE: Endothelin-1 is locally synthesized in the joints of horses with various types of joint disease. Synovial fluid concentrations of ET-1 varied among horses with joint disease, with concentrations significantly higher in the synovial fluid of horses with joint sepsis. These results indicate that ET-1 may play a role in the pathophysiologic mechanism of joint disease in horses.     

Measurements of C-reactive protein in serum and lactate dehydrogenase in serum and synovial fluid of patients with osteoarthritis

Diagnosis of osteoarthritis (OA) is based upon the clinical orthopaedic examination and the radiographic assessment, both of which can be non-specific and insensitive in early joint disease. The aim of our study was to investigate if there is an increase in serum levels of C-reactive protein (CRP) in degenerative joint disease (DJD) and if CRP could be used to help diagnose OA. We also wished to investigate whether it was possible to distinguish a joint with clinically and radiographically confirmed OA from a healthy joint by comparing lactate dehydrogenase (LDH) levels within the synovial fluid and the serum. We have shown a difference in synovial LDH levels between diseased and healthy joints (P<0.0001). There was also a significant difference between LDH in arthritic synovial fluid and serum, with no correlation between the values. Despite the fact that the values of our clinical patients tended to be higher than the values of our control group (P=0.05) all measured values were within the normal limits of previous publications. From these data, we conclude that single measurements of serum CRP do not permit detection of OA in clinical patients and that serum LDH is not a reliable marker for osteoarthritis. LDH levels in the synovial fluid could be of diagnostic value for identifying osteoarthritis.     

Serum amyloid A isoforms in serum and synovial fluid in horses with lipopolysaccharide-induced arthritis

The aim of the study was to determine the intraarticular serum amyloid A (SAA) response pattern in horses with inflammatory arthritis. Inflammatory arthritis was induced by injection of lipopolysaccharide (LPS) into the radiocarpal joint of four horses. Serum and synovial fluid (SF) samples were collected before and at 4, 8, 12, 24, 48, 72, 96, and 144 h after injection. Concentrations of SAA were measured by immunoturbidometry, and expression of SAA isoforms was visualized by denaturing isoelectric focusing and Western blotting. The LPS injection caused systemic and local clinical signs of inflammation. Serum amyloid A appeared in serum and SF within 8 h after LPS injection. Isoelectric focusing showed three major SAA bands with apparent isoelectric points (pI) of 7.9, 8.6, and >9.3 in serum and SF. Synovial fluid contained two additional isoforms with highly alkaline apparent pI values (apparent pI value extrapolated from standard curve = 10.0 and 10.2), which were not present in any of the serum samples. In conclusion, intraarticular injection of LPS induced systemic and local inflammatory responses in the horses. By demonstrating SF-specific SAA isoforms the results of the present study suggest that SAA is synthesized locally in the equine inflamed joint, similar to what has been demonstrated in humans previously. The marked local SAA synthesis suggests an important pathophysiological role in inflammatory arthritis.     

Preliminary observations on the effects of Meloxicam in a new model for acute intra-articular inflammation in dogs

The effects of intra-articular injection, on two occasions, 3 weeks apart, of the contrast agent Urografin on the cytological and biochemical characteristics of synovial fluid (SF) were examined in two studies in dogs. The first study provided baseline data in two non-medicated dogs. The second study used a cross-over design whereby 4 dogs received a 7-day oral treatment with either a placebo or meloxicam (0.2 mg/kg body weight daily) with a washout period of 3 weeks, in order to determine the effect of this new non-steroidal anti-inflammatory drug (NSAID) on the response to Urografin injection. SF samples were collected under general anaesthesia prior to and at 24 and 72 h after each Urografin injection. The volume, relative viscosity, white blood cell count and concentrations of protein, lactate dehydrogenase (LDH) and hyaluronic acid of these samples were determined.The results from both studies indicate that intra-articular injection of Urografin provoked a mild local transient inflammatory response, the most dramatic evidence of which was an increase in the white blood cell count in the SF after 24 h. In the second study, comparison of the synovial fluid measurements of the placebo-treated dogs at 24 h after Urografin injection with those prior to injection revealed significant increases in SF volume, white blood cell count, protein concentration and LDH activity and a significant reduction in relative viscosity. At 72 h after injection, only the white blood cell count and relative viscosity were significantly different from the pre-injection values. All of these measurements were, however, associated with high coefficients of variation, which must be taken into account in assessing the usefulness of the model for drug-testing purposes. Nevertheless, the administration of meloxicam significantly reduced the SF volume and white blood cell count at 24 h relative to the effects of concurrent placebo treatment. The general health status of the animals was not disturbed at any time as assessed by clinical and haematological observations. No adverse reactions were observed.Abbreviations LDH lactate dehydrogenase - NSAID non-steroidal anti-inflammatory drug - SF synovial fluid - WBC white blood cell count     

Tibiotarsal arthroscopy. Applications and long-term outcome in dogs.

The objective of this retrospective article was to describe the use of, and to determine long-term outcome of, tibiotarsal arthroscopy in dogs. The medical records of 20 client-owned dogs with tibiotarsal joint disease with arthroscopic treatment were reviewed. Long-term follow-up evaluation of lameness, force plate gait analysis, and radiographs to assess progression of degenerative joint disease (DJD) were performed. Arthroscopy was utilized in the diagnosis of talar osteochondritis dissecans (OCD), collateral ligament injury, septic arthritis, immune mediated arthritis, and a distal talar fragment. Sixteen joints with OCD treated resulted in 10/14 dogs with lameness after exercise only, progression of DJD in most cases, and chronic lameness when comparing operated to unoperated limbs with force plate evaluation at a mean follow-up of 35 months. Following treatment, three dogs with collateral ligament injury had reduced weight bearing on the operated limb, radiographic progression of DJD, and minimal lameness at a mean follow-up of 27 months. Tibiotarsal arthroscopy can be successfully used to help diagnose, and often to treat: OCD, collateral ligament injury, fractures, septic and non-septic arthritis in the dog. The minimally invasive nature of arthroscopy preserved joint stability while allowing complete examination of the articular cartilage. In most cases long term tibiotarsal DJD advancement was the rule.     

Expression of interleukin-8 and intercellular cell adhesion molecule-1 in the synovial membrane and cranial cruciate ligament of dogs after rupture of the ligament

This cross-sectional clinical study compared inflammation, including expression of the chemokine interleukin (IL)-8 and intercellular cell adhesion molecule-1 (ICAM-1), in the stifle joints of 4 control dogs and 23 dogs with cranial cruciate ligament rupture (CCLR). The CCL, synovial membrane, meniscus, cartilage, and synovial fluid from the affected stifle joints of all the dogs were examined. Inflammatory cell counts were performed on the synovial fluid, and the tissues were processed for histologic study and immunohistochemical detection of IL-8 and ICAM-1. The synovial fluid from the stifle joints of the dogs with CCLR had an increased percentage of neutrophils (P = 0.054) and a decreased percentage of lymphocytes (P = 0.004) but not macrophages compared with the fluid from the control dogs. There was accumulation of inflammatory cells and increased expression of IL-8 and ICAM-1 in the vascular endothelium of the synovial membrane and the CCL of the dogs with CCLR. The increase in inflammatory cells in the stifle joints of dogs with CCLR may therefore be due to increased expression of IL-8 and ICAM-1 in the synovial membrane and the CCL after the injury. These data may help in understanding the mechanisms of inflammation associated with CCLR.     

Thoracolumbar spinal cord compression due to vertebral process degenerative joint disease in a family of Shiloh Shepherd dogs

Five young Shiloh Shepherd Dogs (4 males and 1 female) related by a common sire were studied because of progressive pelvic limb weakness and incoordination. All dogs had a spastic paraparesis and pelvic limb ataxia consistent with an upper motor neuron and general proprioceptive lesion between spinal cord segments T3 and L3. Proliferative lesions involving one or more of the articular processes from the 11th thoracic vertebrae to the 2nd lumbar vertebra were observed on radiographs of the thoracolumbar vertebrae. Dorsal compression of the spinal cord was identified during imaging studies at these sites. Abnormalities of the synovial joints and bony proliferation of the involved articular processes were identified at postmortem examination in 2 dogs. The articular processes and associated vertebral arches protruded into the vertebral canal, indenting the dorsal surface of the spinalcord. Degenerative joint disease (DJD) was identified histologically. A compressive myelopathy was diagnosed in the spinal cord. These dogs were affected by a compressive myelopathy as a consequence of vertebral process DJD that likely has a geneticcomponent. The DJD could have been caused by a primary vertebral malformation or an injury to the processes at a young age causing malarticulation.     

Intraaticular treatment of tarsal degenerative joint disease in cattle.

Tarsal degenerative joint disease (DJD) in 12 cattle was classified as primary or secondary, based on age, evidence of hereditary or congenital joint conformation defects, faulty hindlimb alignment, duration and type of usage joints were subjected to, and history or signs of repeated trauma. Three of the cattle had bilateral primary tarsal DJD, 7 had bilateral secondary tarsal DJD, and 2 had secondary DJD of the left tarsus. Analyses of synovial fluid samples provided a means of characterizing pathologic changes of tarsal DJD, Results of blood and synovial fluid analyses were grouped in compilation of data for cattle affected with either primary or secondary tarsal DJD. Corticosteroids and a long-acting synthetic progestational agent were injected singly or in combination with aqueous antibiotics into affected tarsal joints. Tarsal joints of 5 of the cattle responded favorably to a single intraarticular treatment, as manifested by palliative relief and functionally usable joints. Seven joints of 5 cattle were subjected to repeated intraarticular treatment. Serial synovial fluid analyses in 7 of the cattle provided a means of assessing tarsal joint response to intraarticular treatment or to therapeutic arthrocentesis, exclusive of patient objective response. One cow developed a mild self-limiting bilateral postinjection synovitis that was resolved after the 2nd and final intraarticular injection. Usable function returned to tarsal joints of cattle that responded favorably to intraarticular treatment at different periods after single or repeated injections. Three cattle with advanced tarsal DJD experienced minor temporary relief and were euthanatized at their owner's request. Improvement did not occur in the tarsal joint of 1 cow subjected to therapeutic aspiration only. Intraarticular treatment in all cattle was considered supportive to the animal's well-being rather than curative.     

Evaluation of risk factors for degenerative joint disease associated with hip dysplasia in German Shepherd Dogs, Golden Retrievers, Labrador Retrievers, and Rottweilers.

OBJECTIVE: To determine whether age, breed, sex, weight, or distraction index (DI) was associated with the risk that dogs of 4 common breeds (German Shepherd Dog, Golden Retriever, Labrador Retriever, Rottweiler) would have radiographic evidence of degenerative joint disease (DJD) associated with hip dysplasia. DESIGN: Cross-sectional prevalence study. ANIMALS: 15,742 dogs. PROCEDURE: Hips of dogs were evaluated radiographically by use of the ventrodorsal hip-extended view, the compression v ew, and the distraction view. The ventrodorsal hip-extended view was examined to determine whether dogs had DJD. For each breed, a multiple logistic regression model incorporating age, sex, weight, and DI was created. For each breed, disease-susceptibility curves were produced, using all dogs, regardless of age, and dogs grouped on the basis of age. RESULTS: Weight and DI were significant risk factors for DJD in all breeds. For German Shepherd Dogs, the risk of having DJD was 4.95 times the risk for dogs of the other 3 breeds combined. In all breeds, the probability of having DJD increased with age. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the probability of having hip DJD increased with hip joint laxity as measured by use of DI. This association was breed-specific, indicating that breed-specific information on disease susceptibility should be incorporated when making breeding decisions and when deciding on possible surgical treatment of hip dysplasia.     

Evaluation of a radiographic caudolateral curvilinear osteophyte on the femoral neck and its relationship to degenerative joint disease and distraction index in dogs

OBJECTIVE: To determine prevalence of a radiographic caudolateral curvilinear osteophyte (CCO) on the femoral neck in various breeds and age groups of dogs and to evaluate its contemporaneous relationship with degenerative joint disease (DJD) and distraction index (DI). DESIGN: Cross-sectional prevalence study. ANIMALS: 25,968 dogs, including 3,729 German Shepherd Dogs, 4,545 Golden Retrievers, 6,277 Labrador Retrievers, and 1,191 Rottweilers. PROCEDURE: Data from the University of Pennsylvania Hip Improvement Program database were analyzed, including ventrodorsal hip-extended, compression, and distraction radiographs. The CCO and radiographic signs of DJD were considered independent events and were interpreted as either present or absent. Statistical methods were used to evaluate the CCO as a possible risk factor for DJD and assess its association with DI, as measured by use of distraction radiography. RESULTS: When all breeds were pooled, DJD was detected in 8.6% of dogs, and the CCO was detected in 21.6% of dogs. Among dogs with a CCO, 25.1% had radiographic evidence of DJD. Among dogs without a CCO, only 4% had DJD. Dogs with a CCO were 7.9 times as likely to have DJD as were those without a CCO. Additionally, DI, weight, and age were significant risk factors for the CCO. CONCLUSION AND CLINICAL RELEVANCE: Results confirm the contemporaneous association between the CCO and DJD and that passive hip laxity, as measured by use of the DI, is associated with both the CCO and DJD.     

Measurement of glycosaminoglycans and keratan sulphate in canine arthropathies

Glycosaminoglycans (gag) and keratan sulphate (ks) were measured in sera and synovial fluids from dogs with either osteoarthritis (oa) or rupture of the cranial cruciate ligament (ccl) and normal dogs. The dogs with oa had higher synovial fluid gag levels (P<0·002) and serum KS (P<0·03) compared to the normal dogs. No significant differences in serum gag were found in either group. In both oa and rupture of the ccl, gag levels were increased in the synovial fluid from the affected joint compared with the clinically normal (inactive) contralateral joint. Neither gag nor ks measurements correlated with serum and synovial fluid antibodies to collagen type II, synovial fluid white cell count or age of dog. It is unlikely that the measurement of these cartilage breakdown products is of value for diagnostic or prognostic use in canine arthropathies.     

Changes in concentrations of biochemical markers of osteoarthritis following surgical repair of ruptured cranial cruciate ligaments in dogs.

OBJECTIVE: To investigate longitudinal changes in concentrations of the 1/20/5D4 epitope (5D4) of keratan sulfate and total sulfated glycosaminoglycans (S-GAG) in synovial fluid and serum of dogs with cranial cruciate ligament (CCL) rupture that was repaired via intra-articular surgery. ANIMALS: 58 dogs with a ruptured CCL and osteoarthritis of the affected (index) joint. PROCEDURE: Prior to surgical repair of the ruptured CCL, 5D4 concentration was measured in serum and synovial fluid samples by use of an inhibition ELISA, and total S-GAG concentration was measured in synovial fluid samples by use of a direct dye-binding assay. Ruptured CCL were repaired surgically, using an intra-articular fascial graft. Dogs were reexamined 1.5, 7, and 13 months after surgery, and 5D4 and S-GAG concentrations in synovial fluid and serum were measured again. RESULTS: Serum 5D4 concentrations did not change significantly during the study. Concentrations of 5D4 in synovial fluid (expressed as a ratio of S-GAG concentration) did change significantly with time. In the index joint, the 5D4:S-GAG decreased from 0.19 at the beginning of the study to 0.09 1.5 months after surgery, but 7 months after surgery, the ratio increased again to 0.20. CONCLUSIONS AND CLINICAL RELEVANCE: Results support the hypothesis that serum concentration of 5D4 is not a useful marker of osteoarthritis in dogs. Surgical intervention transiently reduced the concentration of 5D4 in synovial fluid but had no effect on S-GAG concentration.     

Phospholipid compositions of sera and synovial fluids from dog, human and horse: a comparison by 31P-NMR and MALDI-TOF MS

Alterations of the phospholipid (PL) compositions of body fluids are assumed to be indicative of inflammatory diseases, e.g. rheumatoid arthritis (RA). Recently, we have shown that particularly the phosphatidylcholine/lysophosphatidylcholine (PC/LPC) ratio determined in human synovial fluids (SF) and sera represents a reliable measure of the inflammatory state in RA patients. However, it is not yet clear to what extent the PC/LPC ratio is also affected by nutrition habits. In the present study, the PL and the corresponding acyl chain compositions of human body fluids (SF and serum of RA patients as well as serum from healthy volunteers) are compared with those of two other mammalian species (horses and dogs suffering from degenerative joint diseases as well as healthy controls) by high-resolution 31P-nuclear magnetic resonance (NMR) spectroscopy and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS). The most important result of this study is that the PL compositions of SF and serum of horse and dog are comparable with those of human body fluids. Compared with humans, however, the horse body fluid contains less PCs with highly unsaturated arachidonoyl residues, while that of dogs possesses the highest content of arachidonoyl-containing PC. These species-related differences stem primarily from different nutrition habits (meat vs. plants).     

Synovial Fluid Studies in Navicular Disease

The purpose of this study was to investigate biochemical changes in synovial fluid in navicular disease, and to establish if synovial fluid from the distal interphalangeal joint (DIP) could be used diagnostically to assess alterations in the synovial fluid of the navicular bursa. Cartilage oligomeric matrix protein (COMP), total glycosaminoglycans (GAG), hyaluronan (HA), metalloproteinases 2 and -9 (MMP-2 and MMP-9) and total protein (TP) levels were determined in synovial fluids obtained from 18 navicular bursae and 35 DIP -joints from animals suffering from navicular disease, and the same synovial structures in 16 joints of horses with no evidence of abnormalities involving the foot. To avoid dilution effects, GAG/COMP, HA/COMP, MMP-2/ COMP and MMP-9/COMP ratios were also calculated for different synovial cavities. There was a good correlation, for COMP, GAG, HA, MMP-2 and TP levels, between synovial fluid from the navicular bursa and fluid from the DIP -joint in healthy animals. However, in animals with navicular disease, only COMP levels showed no difference between the navicular bursal fluid and the DIP-joint fluid concentration. Thus, enabling the use of COMP to standardise other biochemical concentration measurements from the synovial joint fluids. In horses with navicular disease, there was a significantly lower absolute concentration of GAG, and a significantly lower GAG/COMP ratio, in the synovial fluid of the navicular bursa and the DIP-joint compared to synovial fluid from the same joints from healthy horses. In contrast, the absolute HA concentration and HA/ COMP, MMP-2/COMP and MMP-9/COMP ratios were higher in synovial fluid from the DIP-joint of horses with navicular disease, and MMP-2 and MMP-9 relative activity levels and MMP-2/COMP and MMP-9/ COMP ratios were increased in fluid from navicular bursae in horses with navicular disease when compared to a control group.     

A retrospective study of 40 dogs with polyarthritis

OBJECTIVE: To characterize the epidemiologic, clinical, laboratory, and radiographic findings from dogs with polyarthritis (PA). STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Forty dogs. METHODS: Medical records of 40 dogs with a diagnosis of PA were reviewed. Retrieved data included breed, age at admission, sex, weight, clinical signs, and the results of synovial fluid analysis, complete blood count, serum chemistry profile, urinalysis, serologic screening tests for infectious diseases, and radiographic examination of affected joints. RESULTS: The incidence of PA was 0.37%. Twenty-nine breeds were represented; 16 dogs were male, and 24 were female. Mean body weight was 20.1 +/- 15 kg. The mean age at admission was 5.6 +/- 4 years. Eighty percent of dogs with PA had difficulty or reluctance walking, 35% were lame, 33% had spontaneous vocalization without any obvious reason, 20% had exercise intolerance, 18% were febrile, and 7.5% had an inability to rise or move. Joint pain was identified in 40% of dogs. Synovial fluid color varied from colorless (36%) to yellow-tinged (36%) or hemorrhagic (28%). Synovial fluid mean cell count varied from 10 cells (400x) to 50 cells (1,000x). Leukocytosis occurred in 59% of the dogs and was more frequently identified in dogs with very severe synovial inflammation. Thirty-one percent of affected dogs were anemic. Serum biochemical profiles were considered abnormal in 13% of the dogs. Joint radiography did not identify erosive arthritis. CONCLUSIONS: PA is a common cause of locomotor abnormalities in dogs; however, true lameness and articular pain are not common clinical findings in dogs with PA. CLINICAL RELEVANCE: PA should be considered in the differential diagnosis for all dogs with difficulty walking.     

Effect of Repeated Arthrocentesis on Cytologic Analysis of Synovial Fluid in Dogs

Background: Serial arthrocentesis and synovial fluid examination can be used to monitor treatment efficacy in immune-mediated polyarthritis (IMPA), but whether this procedure induces inflammation that interferes with test result interpretation is unknown.
Objectives: The aim of this study was to determine the effect of repeated arthrocentesis on synovial fluid cytology in healthy dogs.
Animals: Nine healthy client-owned dogs.
Methods: Prospective study. Arthrocentesis was performed under sedation on 4 joints (both carpi, 1 tarsus, 1 stifle) on each dog every 3 weeks, a total of 4 times. Automated cell counts were done on stifle fluid, smears were made, and differential cell counts done on smears from all joints. Slides were evaluated microscopically for erythrocyte numbers, total nucleated cell count, differential cell count, and cell morphology. Data were analyzed by 2-way analysis of variance.
Results: A total of 144 synovial fluid samples were examined. Repeated arthrocentesis was not associated with increases in synovial fluid neutrophil numbers. Mild mononuclear inflammation was detected in 13 samples from 6 dogs.
Conclusions and Clinical Importance: Serial arthrocentesis at 3-week intervals can rarely be associated with mild mononuclear joint inflammation, but does not appear to induce neutrophilic inflammation, at least in healthy dogs, and can be useful to monitor treatment response in canine IMPA.