Interpretation of specialty exams

The specialty exam results allowed us to rule out fracture and a defect (congenital or acquired) as the cause of lameness.  Radiographs looked fairly normal, though we did feel like we were seeing a little increased radiolucency above the fetlock joint and were unsure if this was just due to it being a foal with active growth plates or perhaps the beginning of osteomyelitis.  We might be detecting subtle widening of joint spaces due to synovial effusion from local inflammation.  There was soft tissue swelling apparent on he lateral view, around both the fetlock and pastern joint (though more evident in the fetlock joint).  This is consistent with the pitting edema noted on physical exam and is most likely due to local inflammation.
The CBC had a few minor abnormalities that we are having a hard time explaining.  Though red blood cell count was normal, the cells are smaller than normal (reduced MCV) with apparently increased hemoglobin per cell (MCHC) - but we learned in clinical pathology that a true hyperchromic condition in the red cells is not likely (or possible).  The best explanation for apparent hyperchromia is hemolysis, but if the sample were hemolyzed we'd expect to see increased MCH as well.  The decreased hemoglobin and hematocrit could also be explained by hemolysis...  The increased platelet count is consistent with splenic contraction from epinephrine release (stress of sample acquisition), but we'd expect to see a polycythemia as well.  Perhaps there is a polycythemia that we're not detecting because of rough sample handling and hemolysis, leading to the apparently contradictory other red blood cell information.  
There was elevated fibrin detected in the CBC, which is consistent with inflammation.  No increase in white blood cells was noted, though leukocytes were found in the joint tap.  We think that there is an inflammatory response going on in the joint, but that we've caught it early enough that there aren't obvious systemic changes yet.  The diagnosis of septic arthritis secondary to trauma is supported by the culture of Klebsiella from the joint fluid.  Klebsiella is a coliform bacteria that would have been acquired from environmental contamination (Klebsiella is a common cause of suppurative infections in foals - though this foal doesn't yet have a suppurative infection, one would probably develop in time without treatment).