Canadian beef producers should stay alert to the Asian longhorned tick, an invasive tick that continues to spread in U.S. states close to Canada. Although the tick has not appeared in Canada, awareness still matters.
This matters because the parasite the tick can carry — Theileria orientalis Ikeda — was found in an imported dairy cow in October 2025. As a result, the case shows why producers across all cattle sectors should stay informed.
What is the Asian longhorned tick?
The Asian longhorned tick (Haemaphysalis longicornis) reproduces quickly and thrives in pasture settings. Because of this, tick numbers can rise fast once the species becomes established.
In areas where the tick has spread, producers report heavy tick loads and added stress on cattle. Most importantly, the tick can carry Theileria orientalis Ikeda, which causes bovine theileriosis.
Why this matters for beef operations
In beef cattle, infection may cause:
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Fever and low energy
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Anemia
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Slower weight gain
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Lower overall performance
Because beef cattle spend long periods on pasture, exposure risk can increase through grazing and animal movement. For this reason, early awareness helps protect herd health and performance.
New fact sheet now available
To help producers prepare, a new fact sheet offers clear and practical guidance. Specifically, it explains:
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What to watch for in your herd
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Key signs of bovine theileriosis
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Steps to reduce risk
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How and where to report ticks
The fact sheet was developed by Animal Health Canada with support from the Canadian Animal Health Surveillance System (CAHSS) Longhorned Tick Task Force. Together, the group aims to improve awareness and support early action across the beef sector.
📄 Access the fact sheet here
