Excerpt from Better Pork magazine article authored by Dr. Hollyn Maloney of Prairie Swine Health Services:
Prevention Ear necrosis signals that changes are needed to improve pig performance.
Ear necrosis has multiple causes. The term necrosis means death of body tissue and is an irreversible process. Ear tip necrosis is painful and is a welfare concern. It is also a warning sign that something is wrong in the barn that may lead to mortality and reduced production performance.
Disease process
Ear necrosis can be caused by damage to the outside of the ear, inflammation within the body, or compromised blood flow to the ear.
Fighting can cause damage to the outside of the ear. Bacteria can colonize the damaged tissue. The bacteria Staphylococcus hyicus is a common invader of open wounds. This is the same bacteria that causes greasy pig disease.
S. hyicus creates a film over the wound that allows it to proliferate and allows other bacteria to move into the area. Bacterial proliferation causes necrosis and slowly eats away at the edge of the ear.
Bacterial colonization can cause the tissue around scratches to become red and swollen. A dry brown crust may cover mild injuries. This crust can become thick and moist as further tissue erosion and bacterial growth occurs.