Active use of coyotes (Canis latrans) to detect Bovine Tuberculosis in northeastern Michigan, USA

Abstract

Bovine tuberculosis (bTB) is endemic in white-tailed deer (Odocoileus virginianus) in northeastern Michigan, USA, and research suggests transmission to cattle. Prevalence of the disease in deer is estimated at 1.8%, but as prevalence decreases the difficulty of detection increases. Research suggests coyotes (Canis latrans) have a higher prevalence of bTB in Michigan than deer and sampling coyotes may be a more efficient surveillance tool to detect presence or spread of the disease. Coyotes possess suitable ecological characteristics to serve as a sentinel species, assuming transmission between coyotes is not significant. The question of whether free-ranging coyotes shed Mycobacterium bovis, the causative agent of bTB, has not been previously addressed. We actively used coyotes as a sentinel to detect bTB in infected and uninfected counties in Michigan's Northeastern Lower Peninsula. We determined whether bTB infection was present through bacteriologic culture of lymph nodes and tissues containing lesions and cultured oral/nasal swabs and feces to establish shedding. Seventeen of 171 coyotes were M. bovis culture positive, one of which was from a previously uninfected county. All oral, nasal secretions and feces were culture negative suggesting minimal, if any, shedding of M. bovis. Thus, infection of coyotes is likely to occur through ingestion of infected deer carcasses and not from interaction with conspecifics. These findings support previous research suggesting that coyotes are useful sentinels for bTB. The use of coyotes as a sentinel, may allow wildlife managers to detect the spread of bTB into naïve counties. With earlier detection managers may be able to take proactive surveillance measures to detect the disease in deer and reduce the potential risk to domestic livestock and captive deer herds.

Sources of bovine tuberculosis in the United States

“…These infections in other wildlife were presumably acquired while scavenging on infected deer carcasses (Berentsen et al, 2011), and thus are likely secondary infections, rather than indicators of primary bTB sources. Indeed, 63 of the 82 reports were of strain A, with 42 from coyotes, 14 from opossums, and 7 from raccoons.…”

Mycobacterium caprae transmission to free-living grey wolves (Canis lupus) in the Bieszczady Mountains in Southern Poland

“…Other studies also show that certain carnivorous species, including coyotes, may be used to detect tuberculosis (Berentsen et al 2011). VerCauteren et al (2008 found that obtaining samples from coyotes rather than deer increases the likelihood of detecting Mycobacterium bovis by 40% in TBendemic areas.…”

Assessing the Effectiveness of Tuberculosis Management in Brushtail Possums (Trichosurus vulpecula), through Indirect Surveillance ofMycobacterium bovisInfection Using Released Sentinel Pigs

“…In general, the use of wildlife sentinel species to monitor environmental disease trends has been reported elsewhere for a variety of zoonotic diseases [56–58] and for diseases of agricultural importance, including for monitoring bovine TB [15, 16]. However, such studies have focussed mainly on using wildlife sentinels to monitor patterns of geographic spread of infection within an environment and into previously unaffected areas.…”

“…Pigs develop readily identifiable tuberculous lesions in primary predilection sites draining the oropharyngeal cavity, especially the submaxillary lymph nodes [12], but despite high levels of infection they seldom pass on M. bovis infection to conspecifics under New Zealand conditions [13], even though that does occur in some parts of Mediterranean Europe [14]. Carrion-feeders/scavengers have been used as sentinels for TB in other wildlife maintenance hosts, for example, coyotes ( Canis latrans ) in North America being used to indicate persistent M. bovis infection in white-tailed deer ( Odocoileus virginianus [15, 16]). A recent report has suggested that Virginia opossums ( Didelphis virginiana ) may also provide surveillance potential for persistent TB in North America [17].…”