Red deer with intoxication caused by acorns

In late September, a Red Deer (Cervus elaphus) was found in National Park De Hoge Veluwe. The animal laid on the ground and stayed there even when a person approached closer. Eventually the deer was shot and killed. The person who reported the animal to us, a game warden for the area, explains how they discovered the animal:
“While on duty as game warden, I received a report from visitors about a red deer. When I arrived at the scene, the animal looked unwell. She laid with her neck stretched forward and I could approach her within 10 meters. Nothing about the animal suggested any intention to stand up or flee.”

The Red Deer was transported to the DWHC for post-mortem investigation. During the necropsy, blood in the abdominal cavity was found, caused by the bullet used for the shot. In addition, there was extensive damage and even necrosis of the kidney. The forestomachs were inflamed and filled with acorns. This Red Deer suffered from acorn intoxication.

Acorn intoxication

A warm late summer causes unripe acorns to drop from the trees early, leaving many green acorns on the ground. These unripe acorns contain relatively high tannin, more than ripe brown acorns. Tannin is a toxic substance for several herbivores when ingested in large amounts. Tannin binds proteins that then precipitate in the kidneys and the gastrointestinal tract. This can cause damage there. The animal may move and react slower and fail to ingest enough food. Ultimately it can also cause bloody nose discharge, kidney damage, and bloody diarrhea.

The examined Red Deer was found in the Koeverbos in National Park De Hoge Veluwe. Koeverbos itself is a large area that is normally closed to the public. The game warden tells us about the forest: “The Koeverbos consists almost entirely of Scots pines. On the west side of Koeverbos lies the Bunterbos, almost entirely composed of oaks—native oaks as well as American oaks. On the east side of Koeverbos lies the Franse Berg, almost entirely consisting of native oaks. These could be the places where this Red Deer went to forage.”