Gastrointestinal parasites are a serious health concern for North American bison, but the drugs used to control them may be losing their effectiveness. A new study highlights a gap in current parasite management practices: deworming treatments are often applied too broadly and too often, without checking which animals truly need them.
According to the research, frequent use of these drugs can make them less reliable over time. When producers treat entire herds without first identifying infected individuals, they increase the risk that parasites will become resistant to the medications.
The findings point to a need for more targeted treatment strategies. Rather than relying on routine, blanket deworming, producers may need better tools and guidelines to determine when and which bison should receive parasite drugs.