Hypothesis # 3

Septic Arthritis

Elevated respiratory rate.
Slightly elevated temperature.
Soft tissue swelling (pitting edema).

Entry of bacteria into capsular and/or joint space, following a systemic 
infection is possible.  The infection may have bgeen transient and / or mild, 
with a small population of bacteria settling into the right hind fetlock.  This 
joint, with continued exposure to, and support of, small amounts of replicating 
bacteria may progress to an acute, localized inflammatory response.  Such a 
response may be characterized by increased fluid extravasation from surrounding 
blood vessels, as well as increased inflammatory cell populations.  Increased 
pressure on surrounding tissue and structures results in decreased function, and 
increased pain.

The pathophysiuology of inflammation at this joint remains the same as our 
original hypothesis.  The pathogenesis, however, has been updated here.