Veterinary case
Rare tick-borne parasite found spreading on a cattle farm
⚠️ This information is provided for awareness only and does not replace an examination by a veterinarian.
🤖 Summary produced automatically from the scientific publication cited at the bottom of the page.
On a Tennessee farm, lethargic cattle led to the discovery of an exotic parasite spread by an invasive tick, shared with raccoons, opossums, and even the farm cat.
What happened?
In April 2023, the owner of a cow-calf farm in eastern Tennessee reported that his cattle were showing lethargy and general malaise. These signs resembled theileriosis, a disease caused by a tick-borne parasite. The farm had already been part of a tick surveillance program since 2020, allowing researchers to re-test tick samples collected in previous years for the parasite.
What did the vet find?
The affected cattle were tired and listless, with no other specific signs described. Veterinarians analyzed Asian longhorned ticks collected from cattle, wildlife, and the farm cat. Some of these ticks carried the DNA of a parasite called Theileria orientalis Ikeda, which causes bovine theileriosis, while the blood of the animals themselves did not contain the parasite.
What did the vet do?
ℹ️ Treatment given to THIS animal, decided by its veterinarian. It is not a prescription: never apply it without veterinary advice.
No specific treatment for the sick cattle is described in this case; the work focused mainly on tick detection and control. The farmers had already closed the herd (no new animals entering the farm), managed pastures, and treated animals with tick-killing products even before the parasite was confirmed.
What happened next?
Despite these measures reducing the tick population by about 68%, cattle on the farm were still confirmed positive for the parasite three years after efforts began. The parasite was also found in raccoons, opossums, and a cat living on the farm, showing that several animals contributed to the spread of infected ticks.
Advice for the farmer
To limit the spread of this parasite, it is advised to regularly treat livestock and companion animals against ticks, change gloves and needles between animals, and keep the herd closed as much as possible.
Source
- Source
- PubMed Central
- Title
- Case Report: Retrospective discovery of Theileria orientalis Ikeda in Haemaphysalis longicornis Neumann ticks on a cow-calf farm in Tennessee (US).
- Authors
- Butler RA, Muller LI, Poh KC, Aguilar M, Hokkanen-Harmon KS, Chandler JG, Grove D, Trout Fryxell RT.
- Year
- 2026
- DOI
- 10.3389/fvets.2026.1770304
- Licence
- CC BY
