Specialty Exam Results Radiographs The radiographs revealed that there is an intra-articular soft tissue opacity within the left stifle joint space. This was an expected find since effusion of the stifle joint was noted during the physical examination and evidence of cranial cruciate ligament rupture was found during the orthopedic examination. The intra-articular fat pad has also been compressed in a craniodistal direction. This type of compression may occur with any intra-articular swelling. There is no evidence of subluxation of the stifle joint. However, cranial cruciate ligament rupture does not always produce a visible radiographic displacement. There is no visible indication of degenerative joint disease such as osteophyte and enthesophyte formation or subchondral bone sclerosis. The presence of fractures was also not observed. Clinical Pathology The Hematology report revealed that the WBC count is slightly elevated. The reference range is 3.2 to 10.4 and Bonnie's WBC count is 12.704. This can be explained by the fact that inflammation is occurring in the stifle joint which is causing an increase in demand for cell lines such as neutrophils and monocytes. The bone marrow responds to this increased demand by making more phagocytes available in the blood. The Chemistry Profile revealed two data abnormalities. The albumin and calcium levels were both below the reference ranges. However, upon correction of the calcium value, the calcium is in fact not low in terms of biologically active ionized calcium in the plasma. The calcium is corrected by the formula: adjusted calcium = measured calcium, mg/dl + ( 3.5 – measured albumin, g/dl). This correction takes into account the fact that 40% of calcium is bound to albumin and is not biologically active. Therefore, this type of hypocalcemia is not associated with clinical signs and does not affect the biologically active concentration. This is a hypocalcemia due solely to hypoalbuminemia. The hypoalbuminemia is due to the inflammation in and around the stifle joint. Albumin is lost in inflammatory exudates due to inflammatory mediators causing the capillaries to become leaky at sites of inflammation. The Joint Fluid Analysis revealed that the synovial fluid was clear but a reddish color instead of the being colorless. The reddish color could be due to blood contamination from the sample collection or an ongoing inflammatory process. However, blood contamination will generally not mix homongeonsly with the joint fluid. An intra- articular inflammatory process will cause a diffuse discoloration of the joint fluid, which was the case with this patient. The good mucin clot indicates that the joint fluid is not deficient in polymerized hyaluronic acid. Deficiency in hyularonic acid can occur if it is being excessively diluted by serum or being degraded by an intense intra-articular inflammatory reaction such as degenerative joint disease. The cell count was approximately 3500 per high-powered field with neutrophils and monocytes predominating. Bacteria were not found in the joint fluid. This cell count is consistent with two possible conditions: traumatic or degenerative. Traumatic is the most likely cause due to the fact that there is no other supporting evidence for a degenerative disease process in the other specialty exams such as the radiographs and trauma is also the best- fit scenario for the history and clinical signs.