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Bovine tuberculosis (TB) is an infectious disease that is caused by the bacteria Mycobacterium bovis. Bovine TB primarily affects cattle, however, other animals may become infected. The disease can be transmitted between wildlife populations and animals raised as a food source (farm animals). Bovine TB in animals may occur in the lungs, but may also occur in the intestines and other parts of the body.
- Legislative Report bTB Program January 2018 Quarterly Update
- Legislative Report bTB Program October 2017 Quarterly Update
- Legislative Report bTB Program July 2017 Quarterly Update
- Legislative Report bTB Program April 2017 Quarterly Update
- Legislative Report bTB Program Jan 2017 Quarterly Update
- Bovine Tuberculosis Zoning Order (As of June 7, 2016)
- Bovine Tuberculosis Memorandum of Understanding (As of June 7, 2016)
- Mandatory Cattle Identification Program Q & A - UPDATED 9/12/2014
- Importing Bovine (Cattle and Bison)
- USDA APHIS Livestock Traceability Q & A
- Michigan Map of Bovine TB Zones (As of 10/13/14)
- Bovine tuberculosis - a disease still worth fighting
After more than two decades of study and testing white-tailed deer for bovine tuberculosis, Michigan has become world-renowned for its research and expertise on managing this serious contagious disease. Over this time, DNR wildlife managers have learned a great deal, including that continued assistance from hunters and others remains vitally necessary to make significant gains in battling bovine tuberculosis into the future.
For information regarding specific questions about the effects of TB on wildlife, domestic animals, or humans, consult one of the agencies listed below:
Michigan Dept of Agriculture & Rural Development
Animal Industry Division
Constitution Hall, 6th Floor
PO Box 30017
Lansing, MI 48909
Atlanta Regional Office
PO Box 758
Atlanta, MI 49709
Michigan Dept of Health & Human Services
Bureau of Disease Control, Prevention, and Epidemiology
201 Townsend St
Lansing, MI 48913
Michigan Dept of Natural Resources
Wildlife Disease Lab
4125 Beaumont Rd
Lansing, MI 48910
Michigan State University Extension
Large Animal Sciences / Beef
A100 Vet Medical Center
East Lansing, MI 48824
Northeast Region / Dairy
101 S. Court St., PO Box 69
Mio, MI 48647
U.S. Dept of Agriculture - Veterinary Services
3001 Coolidge Rd. Suite 325
East Lansing, MI 48823
U.S. Dept of Agriculture - Wildlife Services
2803 Jolly Rd, Ste. 100
Okemos, MI 48864
Gaylord Regional Office
1865 O'Rourke Blvd Ste. C
Gaylord, MI 49735
Wild and Captive Deer and Elk
Click here to see pictures of tuberculosis lesions in wild deer from Michigan
Bovine tuberculosis is a chronic disease, and small lesions in wild white-tailed deer often are not readily recognized. Abscesses may not be visible to hunters when field dressing wild deer. Indeed, most infected white-tailed deer appear healthy. Affected animals may have yellow to tan, pea-sized nodules in the chest cavity or lungs. Lymph nodes of the head and neck can be swollen and necrotic.
Captive cervids with tuberculosis often appear healthy because infection is localized in one or a few lymph nodes, usually in the head or thorax. Tuberculosis is a chronic, progressive disease that can cause gradual debilitation and is manifest as emaciation, depression, and intolerance to exercise. Because infection often involves the lungs, coughing, nasal discharges, and difficulty breathing can occur in severe cases. In some instances, superficial lymph nodes in the neck will develop large abscesses that may rupture and drain through the skin.
At necropsy, tuberculosis lesions are variable in appearance and size. Subclinically infected animals may have one or a few small necrotic nodules that usually are associated with the lymph nodes of the head and neck or the lungs. More severely infected cervids can have multiple pea-sized nodules or large cheesy or pus-filled masses in the same areas. The classical tubercle, which is firm, white or pale yellow, and gritty when cut, does occur in cervids, but many M. bovis lesions in these animals are filled with pus. In cervids, tuberculosis lesions are most often seen in the lymph nodes of the head and neck or in lung tissue; however, lesions can occur throughout the chest cavity, under the skin of the chest, and in the abdominal cavity as well.
(Source of the above text on this page: Field Manual of Wildlife Diseases in the Southeastern United States, 2nd Ed., W.R. Davidson, V.F. Nettles, Southeastern Cooperative Wildlife Disease Study, 1997)
Click here to see pictures of the lungs of a beef cow with bovine TB lesions.
Patterns of infection in cattle are very similar to the above description.
Prevention/Control Methods for People
People can be skin-tested to determine if they are infected with TB. These tests can be done at either the local health department or a private physician's office. A positive skin test, however, does not identify the type or source of the infection. Remember, most people get the infection from other people.
Prevention/Control in Livestock
In the early 1900's, the federal government instituted an eradication program for bovine TB. This program includes testing of livestock on farms and monitoring of animals sent to slaughter or transported across state lines. As a result of this program, bovine TB has nearly been eradicated in cattle in the U.S.
Prevention/Control in Wild Deer
Since there are no effective vaccines for disease prevention and no effective medications for treatment of bovine TB in wild deer, a combination of wildlife disease surveys and deer management strategies are being used to eliminate the disease in wild deer. The wildlife surveys monitor the spread and occurrence of the disease, while hunters are asked to examine their deer from all areas of the state.
The 1998 press release announcing the Executive Directive to the Michigan Departments of Agriculture, Community Health and Natural Resources to jointly develop management plans for eradicating bovine TB in Michigan deer.
- Michigan Bovine Tuberculosis Eradication Project