Nature is awesome. Everyday you can witness amazing feats just by looking out the window. Birds fly. Plants die and are resurrected each spring. Dog poop magically disappears after a few months in the yard. Even when nature behaves badly (pandemics aside), it is still pretty cool.
We are fans of definitions and geeky details around here. So get ready for a knowledge drop!
Syndrome: a group of symptoms which consistently occur together, or a condition characterized by a set of associated symptoms.
Opportunistic: (of a microorganism or an infection caused by it) rarely affecting patients except in unusual circumstances, typically when the immune system is depressed.
Remember that Wicked Migraine. The undoing of this poor unfortunate soul was a brain abscess. A brain abscess is a syndrome. It is a group of symptoms associated with opportunistic bacteria.
The star of most brain abscesses is Trueperella. These modest bacteria are part of the biota of skin and mucous membranes of the upper respiratory and urogenital tracts of animals. They have also been found in the rumen chillin’ with all the other micro-flora and -fauna. It is well behaved in its native environment but it’s an opportunistic bacterium. Meaning when you take it out, it goes crazy. Much like a wildlife veterinarian attending UGA football games or a wildlife biologist going to Disney World.
We see the “crazy” presentation of Trueperella mostly in adult males in the fall and winter. Like all problems in life, this is driven by bad behavior in males. Testosterone and antlers – the double-edged sword of deer. Scraping, rubbing, fighting – all create cuts and scratches in the skin on the head and base of the antler pedicle allowing bacteria to get to places they shouldn’t. Trueperella is happy to walk through the open door of an abrasion in the skin. Then it starts behaving badly working its way through the soft tissues to the skull.
The skull is made of several bones that fit together like puzzle pieces. Those pieces are connected by sutures, fibrous connective tissue, which are more easily penetrated by the bacteria.
Trueperella tears through that connective tissue like a seam ripper invading the brain. At that point, the pressure from the abscess and destruction of the brain tissue (necrosis) causes clinical signs of disease. Which is a fancy way of saying, “hey that deer looks sick.”
Because this is a syndrome, we can see variation. Trueperella isn’t the only opportunistic bacteria hanging around on a deer. Other bacteria (particularly those naturally on the skin or in the environment) can cause brain abscesses as well.
Since brain abscesses are associated with bad behavior in males, it’s rare in females. But it can happen especially when a stick gets lodged in her nasal cavity creating a bacteria super highway to the skull and into the front part of the brain. True story.
Back to our poor unfortunate soul with the wicked migraine. Looking at the jawbone, he was a yearling. And his antlers were hardened with no velvet, so he likely died in September given tooth eruption (last tooth not fully erupted yet).
His first year of breaking bad turned out to be his last.
Dr. Justin Brown and Jeannine Fleegle
