Wildlife Disease Research Program 



TITLE: Controlling Wildlife Vectors of Bovine 

 Tuberculosis 



GOAL: Study the ecology of tuberculosis in wildlife; 

 assess the risk of disease transmission 

 among wildlife, domestic animals, and 

 humans; and develop methods that reduce 

 or eliminate such transmission. 



Bovine tuberculosis (bTB) is a contagious disease 

 affecting wildlife, livestock, and humans caused by 

 the bacterium Mycobacterium bovis. The disease 

 is transmitted through direct contact, inhalation of 

 aerosolized bacilli, or indirect contact via shared 

 feed. Although once common in the United States 

 in cattle, bTB has been historically rare in wildlife. 

 However, since 1994, cases of bTB have been 

 found in Michigan white-tailed deer; and research 

 indicates that the disease is transmitted from deer 

 to other wildlife and cattle by shared feed. 



The presence of a wildlife reservoir for bTB has 

 implications for Michigan's livestock industry. Since 

 1997, cattle on 40 farms and 527 wild white-tailed 

 deer have tested positive for bTB. The situation is 

 exacerbated by the sharing of feed and resources 

 between wild deer and domestic cattle, and most 

 cattle farms have only limited fencing and other 

 techniques suitable for preventing deer access. 



Evaluation of Potential Shedding of M. bovis by 

 Experimentally Infected Coyotes — In cooperation 

 with CSU's departments of Biomedical Sciences and 

 Microbiology, Immunology, and Pathology, NWRC 

 scientists are evaluating the potential shedding of 

 Mycobacterium bovis by coyotes. M. bovis causes 

 bTB in domestic cattle and other animals. In some 

 areas of Michigan, the prevalence of bTB infection 

 in coyotes has been as high as 33 percent. 



In BSL-3 facilities at CSU, four coyotes were 

 inoculated with M. bovis isolates in order to identify 

 whether coyotes are a potential transmission source 

 for bTB. Oral swabs, nasal swabs, feces, and blood 

 samples were taken every 2 weeks. In addition. 



''"snnfiMlHIM 



Oral and nasal swabs are taken from coyotes in order to identify 

 whether they are a potential transmission source for bTB. 



coyote feces were mixed in the bedding litter of 

 guinea pigs to determine if the feces contained 

 enough viable organisms to infect the guinea pigs. 



Preliminary culture results for coyotes have been 

 negative for bTB, and no negative effects were 

 observed in the guinea pigs. Information from 

 this study will be used for APHIS' National Bovine 

 Tuberculosis Eradication Program in the United States. 



Using Coyotes as a Sentinel Species To Detect 

 the Presence of bTB in Michigan — Between 12 

 and 33 percent of coyotes in the bTB-affected 

 area in Michigan are positive for bTB. If they shed 

 M. bovis, coyotes could be an important source 

 of infection for cattle. In this field study, NWRC 

 scientists are determining if coyotes are shedding 

 M. bovis. Another objective is to determine whether 

 the prevalence of bTB in coyotes in Michigan has 

 changed from past years. 



In the parts of Michigan 

 where bTB is endemic, 

 coyotes have had a 

 prevalence of bTB 

 infection as high as 33 

 percent. 



Developing Methods 19 



