Interpretation of Specialty Exams

1. Clinical Pathology: The foalÕs CBC revealed a 
possible microcytic, nonregenerative anemia.  Both 
hemoglobin and the hematocrit were low, but the RBC 
count was within normal limits.  There was no 
reticulocytosis to suggest a proliferative response 
to the anemia.  In addition, the data did not 
clearly 
indicate  whether the anemia was normochromic (low 
normal value for MCH) or hyperchromic 
(slightly increased value for MCHC).  Such an 
anemia could be indicative of a chronic disease 
process 
involving sequestration of iron in macrophages 
creating a deficit for erythropoiesis.  All 
parameters of 
the foals leukogram were within normal limits.  No 
evidence of an inflammatory process was 
detectable systemically.  The CBC did reveal a 
slight thrombocytosis, possibly resulting from the 
excitement of the exam causing epinephrine release 
and splenic contraction.  A slight hypoproteinemia 
was also detected possibly related to recent 
anorexia.  The results of joint fluid analysis 
revealed 
predominantly small mononuclear cells.  These were 
most likely the macrophages and lymphocytes 
normally found in joints.  The mucin clot was good 
indicating a healthy synovial fluid integrity, 
uncompromised by inflammatory mediators.  A pure 
culture of Kleibsiella pneumoniae was grown 
from the joint fluid innoculant.  This organism is 
common in the environment, and considering the lack 
of evidence of an inflammatory response in the 
joint (no PMN cells found on cytology), the 
bacterial 
growth was likely due to contamination.  

2.  Radiographs:  Boney changes were appreciated on 
the medial and lateral aspects of the third 
metatarsus 
(distal extremity just proximal to the fetlock 
joint) on the dorsal/palmar view of the right hind 
fetlock.  
They were radiolucent regions suggesting bony lysis 
in the region of epiphysis.  On the lateral view of 
the 
right hind fetlock, the third metatarsal epiphysis 
was obscured by significant bony change.  Possible 
sclerotic lesions appeared associated with adjacent 
lysis around the epiphysis.  The disruption did not 
appear 
to involve the metatarsal/phalangeal joint.  These 
radiographic findings were suggestive of a septic 
osteomyelitis of the growth plate.  Such a 
condition is usually hematogenous in origin from a 
neonatal 
infection that results in septicemia.