Inflammatory pattern of the infrapatellar fat pad in dogs with canine cruciate ligament disease.

BACKGROUND: Despite the importance of inflammation during the pathogenesis of cranial cruciate ligament disease (CCLD) in dogs and despite the latest knowledge suggesting a significant role of adipose tissue in osteoarthritis, the infrapatellar fat pad (IFP) was up to now mostly disregarded in veterinary investigations. In the present study, the inflammatory activity of the IFP, the main adipose structure within the stifle joint, was thoroughly investigated to evaluate its potential impact in the pathogenesis of this common disease of our canine companions. Samples of IFP, subcutaneous adipose tissue (ScAT) of the thigh and synovial fluid in both diseased (n = 36) and healthy control (n = 23) dogs were tested for their immune cell composition but also for interleukins (IL-1ß, IL-6, IL-8, IL-10), degradative enzymes (MMP-1, MMP-3, MMP-13, TIMP-2, iNOS) and adipokines (leptin and adiponectin). Characterization of the immune cell composition was ascertained by fluorescence activated cell sorting. Gene expression and protein release of the inflammatory markers was determined by real RT-qPCR and ELISA. RESULTS: IFPs of dogs with CCLD had a significantly increased immune cell count with T cells (CD3) as the most abundant immune cells. T cells and macrophages (CD14) were significantly increased compared to healthy controls or corresponding ScAT. In addition, IFPs of dogs with CCLD demonstrated a significant increase on gene as well as protein level of multiple inflammatory indicators (IL-1ß, IL-6, MMP-1, MMP-13) compared to the other tissues. TNFα was only increased on gene expression. Adipokine analysis showed higher secretion of adiponectin and lower leptin secretion in IFP from dogs with CCLD than from controls. In the synovial fluid from dogs with CCLD concentrations of IL-1ß, MMP-1, MMP-13 as well as leptin were significantly increased compared to the synovial fluid from healthy control dogs. CONCLUSIONS: The present study indicates that the IFP is a potential contributory factor in the pathogenesis of CCLD, due to its inflammatory phenotype and the proximity within the stifle joint. To determine the extent of this possible inter-relationship, further studies need to be undertaken.

In vitro cytoprotective effects of acetylsalicylic acid, carprofen, meloxicam, or robenacoxib against apoptosis induced by sodium nitroprusside in canine cruciate ligament cells.

OBJECTIVE: To determine whether incubation of cruciate ligament cells with acetylsalicylic acid, carprofen, meloxicam, or robenacoxib provides protection against apoptosis induced by sodium nitroprusside (SNP). SAMPLE: Explants of cranial (CCL) and caudal (CaCL) cruciate ligaments from eight 1-day-old Beagles. PROCEDURES: Primary cultures of CCL and CaCL cells were created via enzymatic dissociation of cruciate explants. Purified cell cultures were incubated for 2 hours without (controls) or with 1 of 3 concentrations of 1 of 4 NSAIDs (10, 100, or 200 µg of acetylsalicylic acid/mL; 0.1, 1, or 10 µg of carprofen/mL; 0.1, 1, or 10 µg of meloxicam/mL; or 0.1, 1, or 10 µg of robenacoxib/mL) and subsequently incubated for 18 hours with 1 of 3 concentrations of SNP in an attempt to induce mild, moderate, or severe cytotoxic effects. Cell viability and apoptosis were analyzed via a cell proliferation assay and flow cytometry, respectively. Prostaglandin E(2) concentrations were measured via an ELISA. RESULTS: Cytoprotective effects of NSAIDs were dependent on the extent of SNP-induced apoptosis and were greatest in CCL and CaCL cell cultures with moderate SNP-induced cytotoxic effects. Preincubation with an NSAID improved cell viability by 15% to 45% when CCL and CaCL cells were subsequently incubated with SNP. Carprofen (10 µg/mL) had the greatest cytoprotective effects for CCL and CaCL cells. Incubation with NSAIDs resulted in a nonsignificant decrease in PGE(2) production from SNP-damaged cells. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that carprofen, meloxicam, and robenacoxib may reduce apoptosis in cells originating from canine cruciate ligaments.

Evaluation of respiratory parameters at presentation as clinical indicators of the respiratory localization in dogs and cats with respiratory distress.

OBJECTIVE: To describe clinical respiratory parameters in cats and dogs with respiratory distress and identify associations between respiratory signs at presentation and localization of the disease with particular evaluation between the synchrony of abdominal and chest wall movements as a clinical indicators for pleural space disease. Design - Prospective observational clinical study. SETTING: Emergency service in a university veterinary teaching hospital. ANIMALS: Cats and dogs with respiratory distress presented to the emergency service between April 2008 and July 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The following parameters were systematically determined at time of admission: respiratory rate, heart rate, temperature, type of breathing, movement of the thoracic and abdominal wall during inspiration, presence of stridor, presence and type of dyspnea, and results of thoracic auscultation. Abdominal and chest wall movement was categorized as synchronous, asynchronous, or inverse. Diagnostic test results, diagnosis, and outcome were subsequently recorded. Based on the final diagnoses, animals were assigned to 1 or more of the following groups regarding the anatomical localization of the respiratory distress: upper airways, lower airways, lung parenchyma, pleural space, thoracic wall, nonrespiratory causes, and normal animals. One hundred and seventy-six animals (103 cats and 73 dogs) were evaluated. Inspiratory dyspnea was associated with upper airway disease in dogs and expiratory dyspnea with lower airway disease in cats. Respiratory noises were significantly associated and highly sensitive and specific for upper airway disease. An asynchronous or inverse breathing pattern and decreased lung auscultation results were significantly associated with pleural space disease in both dogs and cats (P<0.001). The combination is highly sensitive (99%) but not very specific (45%). Fast and shallow breathing was not associated with pleural space disease. Increased or moist pulmonary auscultation findings were associated with parenchymal lung disease. CONCLUSIONS: Cats and dogs with pleural space disease can be identified by an asynchronous or inverse breathing pattern in combination with decreased lung sounds on auscultation.

Right ventricular rupture after lateral thoracotomy for removal of rib-associated telangiectatic osteosarcoma in a dog.

OBJECTIVE: To describe a case of a focal right ventricular rupture following removal of a rib-associated telangiectatic osteosarcoma (TOS) in a dog. CASE SUMMARY: A 2-year-old spayed female mixed-breed dog, weighing 20 kg, was presented in compensated hypovolemic shock due to active bleeding into the thoracic cavity. The dog was stabilized with appropriate fluid administration. Subsequent computed tomographic examination revealed a large mineralized mass originating from the body of a rib and displacing the heart. Two days after surgical removal of this mass, focal right ventricular rupture occurred and the dog died. The mass was later identified as a TOS. NEW OR UNIQUE INFORMATION PROVIDED: Although hemothorax secondary to TOS has been described previously, this report describes for the first time, spontaneous focal right ventricular rupture as a rare complication of thoracotomy and rib resection for the removal of a rib-associated, intrathoracic TOS.

Apoptosis of ligamentous cells of the cranial cruciate ligament from stable stifle joints of dogs with partial cranial cruciate ligament rupture.

OBJECTIVE: To describe the presence and amount of apoptotic ligamentous cells in different areas of partially ruptured canine cranial cruciate ligaments (prCCLs) and to compare these findings with apoptosis of ligamentous cells in totally ruptured cranial cruciate ligaments (trCCLs). ANIMALS: 20 dogs with prCCLs and 14 dogs with trCCLs. PROCEDURES: Dogs with prCCLs or trCCLs were admitted to the veterinary hospital for stifle joint treatment. Biopsy specimens of the intact area of prCCLs (group A) and the ruptured area of prCCLs (group B) as well as specimens from trCCLs (group C) were harvested during arthroscopy. Caspase-3 and poly (ADP-ribose) polymerase (PARP) detection were used to detect apoptotic ligamentous cells by immunohistochemistry. RESULTS: No difference was found in the degree of synovitis or osteophytosis between prCCLs and trCCLs. No difference was found in degenerative changes in ligaments between groups A and B. A substantial amount of apoptotic cells could be found in > 90% of all stained slides. A correlation (r(s) = 0.71) was found between the number of caspase-3-and PARP-positive cells. No significant difference was found in the amount of apoptotic cells among the 3 groups. No significant correlation could be detected between the degree of synovitis and apoptotic cells or osteophyte production and apoptotic cells. CONCLUSIONS AND CLINICAL RELEVANCE: The lack of difference between the 3 groups indicates that apoptosis could be a factor in the internal disease process leading to CCL rupture and is not primarily a consequence of the acute rupture of the ligament.

Effect of carprofen, etodolac, meloxicam, or butorphanol in dogs with induced acute synovitis.

OBJECTIVE: To compare the analgesic and anti-inflammatory effect of single doses of carprofen, etodolac, meloxicam, and butorphanol in dogs with induced acute synovitis (acute pain model) via kinetic gait analysis and orthopedic evaluation and examine measurement of serum C-reactive protein (CRP) concentration as an indicator of treatment efficacy. ANIMALS: 12 Beagles and 6 additional Beagles that were used only in serum CRP analyses. PROCEDURE: Acute synovitis was induced in right stifle joints of dogs via intra-articular injection of monosodium urate solution. Treatments included butorphanol (0.2 mg/kg, i.v.), carprofen (4 mg/kg, PO), etodolac (17 mg/kg, PO), or meloxicam (0.2 mg/kg, PO); control dogs received no treatment. The procedure was repeated (3-week intervals) until all dogs received all treatments including control treatment. Lameness was assessed on a biomechanical force platform and via orthopedic evaluations of the stifle joints; blood was collected to monitor serum CRP concentration. RESULTS: Compared with control dogs, treated dogs had significantly different vertical ground reaction forces and weight-bearing scores. Greatest improvement in lameness was observed in carprofen-treated dogs. Etodolac had the fastest onset of action. Compared with butorphanol treatment, only carprofen and etodolac were associated with significantly lower pain scores. An increase in serum CRP concentration was detected after intra-articular injection in all dogs; this change was similar among groups. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen, etodolac, and meloxicam had greater efficacy than butorphanol in relief of acute pain. Carprofen was most effective overall. In this acute pain model, serum CRP analysis was not useful to assess drug efficacy.

Effects of stimulus with proinflammatory mediators on nitric oxide production and matrix metalloproteinase activity in explants of cranial cruciate ligaments obtained from dogs.

OBJECTIVE: To evaluate the origin and degree of activity of nitric oxide (NO) and matrix metalloproteinase (MMP) in explants of cranial cruciate ligaments (CCLs) obtained from dogs and cultured with and without inflammatory activators. SAMPLE POPULATION: Tissue specimens obtained from 7 healthy adult Beagles that were (mean +/- SD) 4.5 +/- 0.5 years old and weighed 12.5 +/- 0.8 kg. PROCEDURE: The CCLs were harvested immediately after dogs were euthanatized, and specimens were submitted for explant culture. Cultures were stimulated by incubation with a combination of interleukin-1, tumor necrosis factor-alpha, and lipopolysaccharide, or they were not stimulated. Culture supernatants were examined for production of NO nitrite-nitrate metabolites (NOts) and activity of MMP Cultured specimens were evaluated by use of immunohistochemical analysis to detect activity of inducible NO synthase (iNOS). RESULTS: All ligament explants produced measurable amounts of NOts. Stimulated cultures produced significantly more NOts after incubation for 24 and 48 hours, compared with nonstimulated cultures. Production of MMP in supernatants after incubation for 48 hours was significantly higher in stimulated cultures than in nonstimulated cultures. Cells with positive staining for iNOS were detected on all slides. Positively stained cells were predominantly chondroid metaplastic. There was a significant difference in intensity of cell staining between stimulated and non-stimulated cultures. CONCLUSIONS AND CLINICAL RELEVANCE: Explant cultures of intact CCLs obtained from dogs produce iNOS-induced NO. Stimulation of chondroid metaplastic cells in CCL of dogs by use of inflammatory activators can increase production of iNOS, NOts, and MMP.