HYPOTHESIS 1: TRAUMA

Trauma is a reasonable hypothesis due to the fact that only one joint appears to 
be 
affected and the foal has not changed its behavior and is not showing signs of 
acute 
inflammation such as temperature or inappetance.  

There are many forms of trauma that could support the physical findings, 
clientÕs 
complaint, and history.  The most likely form of trauma for a foal of this age 
would be a 
blunt force trauma such as the mare stepping on the foal.  This is what the 
owners think 
has happened.  However, the foal could have inflicted blunt force trauma on 
itself by 
rough housing and bumping into things in the stall.   Other than blunt force 
trauma, the 
next likely form of trauma could be a puncture wound from most likely a nail.  

Blunt force trauma would most likely result in soft tissue damage to the nerves, 
tendons, 
ligaments, and/or musculature or in bone damage.  

The result of soft tissue damage would be localized swelling and pain.  The foal 
does 
have swelling only the fetlock region, is resentful of palpation of this area 
and does have 
a positive flexion test.  The foal is also displaying toe touching lameness, 
which is 
another indicator of pain.    Upon further examination with radiographs we would 
expect 
to find increased fluid density.  With ultrasound, we would expect to get a 
better 
appreciation of the soft tissue structures and to better localize where the 
actual problem 
is.

The result of bone damage would most likely be bone fracture.  Localized 
swelling, pain, 
and lameness could accompany this also.  With radiographic examination, we would 
expect to find evidence of fracture and also be able to visualize the 
accompanying soft 
tissue swelling.  

Puncture wound trauma would be accompanied with a physical finding of where the 
object penetrated the skin.  However, this may be difficult if the puncture area 
was small 
and the area healed over quickly.  Puncture wounds would likely set up an 
infection, 
possibly septic arthritis, due to bacterial contamination of the puncture 
object.  The 
pitting edema, pain, and accelerated respiration are good indicators of 
inflammation in 
this foal.  Upon radiographic examination, with septic arthritis we would expect 
to see 
evidence of periarticular swelling, joint capsule distention, and possibly 
marginal bone 
lysis and subchondral bone lysis.