My sheep has a lump on her shoulder

[bomi79]

My sheep has a lump on the front of her shoulder. I drew blood and had it tested for CL. Thank goodness it came back negative. But I still don't know what the lump is!
Anyone have any ideas?

 

[aggieterpkatie]

Could it possibly be a vaccine lump? Or possibly an abcess from an injury?

 

[rockdoveranch]

Insect sting? Snake bite?