Bacterial Infections From Brucellosis Can Cause Mid-Winter Abortions In Elk

Nov 12, 2018

Elk feed in large groups at winter feed grounds which make them susceptible to bacterial infection from Brucellosis.
Credit Mark Gocke, WY Game & Fish Dept

For decades, researchers have known that the bacterial infection Brucellosis can cause deaths in cattle and bison herds in the western US. 

But new research from Gavin Cotterill, a Ph.D. candidate in the department of wildland resources at Utah State University revealed that the bacteria can also cause mid-winter abortions in elk.

"Elk are typically infected through direct contact with the products of these abortion events so fetuses that are on the landscape or placental fluids. And in western Wyoming, there are 23 winter feed grounds for elk that aggregate these animals during a time of year when they are at risk of aborting," Cotterill said. 

Researchers and land managers already use predation from wolves and lack of food due to drought to better understand mid-winter pregnancy rates. Additionally mid-winter pregnancies are used to assess the health of elk populations to set hunting regulations.

"In terms of managing elk populations, and Brucellosis, I think right now the thing that most people are focused on is the spread of the disease to herds that historically have not had the disease, so it is spreading to new regions in eastern Wyoming and beyond," he said. "And depending on what other things are impacting those herds this might be a highly relevant thing to know just in terms of herd demography and overall herd health. Part of this puzzle for managers and everyone else is what changes are we seeing on the ground that’s leading to the spread of the disease to new herds. If we’re seeing big increases in the disease in migratory herds that are already suffering from the effects of long term drought or something like that then this is definitely something that those folks would be interested in."

According to Cotterill, more research is needed to better understand these bacterial mechanisms and the impact on elk populations throughout the West.