What's A Seroma?

The technical definition is a pocket of serum underneath the skin that usually develops after surgery. 

 The not so technical is a big swelling like a water balloon on Draper's shoulder for no apparent reason.  I went to catch her last week for the farrier to reset her shoes, and found this big thing.  It was swollen down to her knee, but not causing any lameness. 

 I was pretty sure it was a seroma, I didn't see any punctures and it wasn't painful like an abscess would be.  I gave her the week off to see how it would progress.  Well, it looked the same but the rest of the swelling down to the knee was gone.  So it was time to take action.

 I clipped and scrubbed the area and tapped it with an 18 gauge needle.   I didn't measure the amount that came out but it was a good 200+ cc's.

It's is flat again for the time being, but may reform.  Hopefully, if it does it will be smaller.  I have had to drain some on dogs up to 3 times before they finally went away, but once is more the norm.   This one probably occurred after some type of trauma, maybe she ran into something out in the field or got kicked by one of the other horses.  Too bad they can't tell us what happened.