Documenting what Southwest herds are carrying
Many of the pathogens that circulate in food animal herds also affect people - through food safety, zoonotic disease, and ecological health. We perform disease surveillance and treatment on the most at-risk food animals in our region, the culls. Our mission is to support One Health disease education and research for Southwest herds.
See Where Disease Is Active in the Southwest
An interactive county map of 9 livestock diseases across Arizona, New Mexico and Texas: active outbreaks, past cases, species affected and which diseases must be reported. Records come from USDA, state agencies and the sources in 3T’s guides.
- 302counties
- 9diseases
- 3states
Diseases we document
Human, animal and environmental health form one system. Pathogens move between them through shared ground, shared water and daily contact. Livestock sit at the center of that exchange, handled by people every day and sharing land and water with wildlife.
Leptospirosis
Reproductive losses in cattle, including abortion, stillbirth, weak calves, infertility, and sudden reductions in milk production. Many infected cattle show no obvious signs of illness.
Brucellosis
Abortion in cattle, often between the fifth and ninth month of pregnancy, with retained placenta, stillborn or weak calves, and reduced fertility. In bulls, infection can cause orchitis (testicular inflammation) and infertility.
Foothill Abortion
Late-term abortion and weak calves in cattle. The cow usually shows no obvious signs.
Valley Fever
Usually causes no recognizable illness in cattle. Infection may be discovered at slaughter as granulomatous lesions in the lungs and chest lymph nodes that resemble tuberculosis.
Bluetongue
Sheep are the most clinically important domestic host. Signs can include fever, facial and muzzle swelling, mouth lesions, lameness, and death.
New World Screwworm
The larvae of the New World screwworm fly feed on living tissue in wounds and body openings of warm-blooded animals. Untreated infestations can cause severe tissue damage, secondary infection, and death.
Listeriosis
Primarily affects cattle, sheep, and goats. The most recognizable form is a brain infection that causes one-sided facial weakness, difficulty chewing and swallowing, drooling, circling, and depression.
Vesicular Stomatitis
Blisters and painful sores on the mouth, tongue, lips, feet, teats, and sheath of horses, cattle, pigs, and camelids, and less commonly in sheep and goats. Drooling and reluctance to eat are often the first signs.
Bovine Tuberculosis
A slow, chronic infection of cattle, bison, and other mammals that often produces no obvious signs for years. Most infected cattle herds are detected through slaughter surveillance or official testing, not by producers noticing sick animals.
Most cull animals are never diagnosed
Animals are culled for a reason: illness, falling production, or age. That reason is rarely established. Slaughter inspection determines whether a carcass is fit for food, not why the animal left the herd. Targeted diagnostics could answer that question, and develop a fingerprint of one health diseases in the region.
3T Ranch will purchase cull animals, complete targeted surveillance testing, and publish the findings to establish a public database of the diseases affecting Southwest herds.
Stay ahead of disease in Southwest herds
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Leadership and board
Dr. Hannah Varnell
Dr. Varnell founded Three Trails to record livestock disease that currently goes undocumented. Her focus is global health and food animal epidemiology.
Board of Directors
- Hannah Varnell, DVM, DACVPMExecutive Director
- Johanna Klomann, CPADirector & Treasurer
- Whitney SlighthamDirector