Risk of pathogen spillover to bighorn sheep from domestic sheep and goat flocks on private land

Abstract

Bighorn sheep (Ovis canadensis) across North America have suffered population losses due to polymicrobial pneumonia typically initiated by spillover events of bacteria from domestic sheep and goats. Because vaccination or treatment of individual animals remains an elusive goal and pneumonia often persists in bighorn herds for years or decades following infection, preventing contact between domestic and wild animals is widely accepted as the best prophylactic. For the past decade, most management efforts have focused on the risks associated with commercial sheep grazing on public lands; less attention has been paid to risks to bighorns from small flocks of domestic sheep and goats managed entirely on private land. We surveyed owners of 40 sheep or goat flocks located near bighorn sheep herds in central and southeastern Washington, USA, during 2014 and 2015, to better understand their knowledge level, management practices, and willingness to reduce risks. Over one-third of sheep or goat owners had no knowledge of the potential for pathogen spillover to bighorns, but all were interested in reducing risk of interacting with bighorns, particularly by options that did not restrict their autonomy. We also sampled nasal mucosae of 137 animals in 24 flocks for presence of Mycoplasma ovipneumoniae, the bacterium most closely associated with bighorn pneumonia. M. ovipneumoniae was detected in 37.5% of sheep or goat flocks sampled, and animals had escaped their enclosures in 78% of these. Physical contact, and thus pathogen spillover from domestic sheep or goats living in small, private flocks in close proximity to bighorns is clearly a risk. We provide recommendations to agency staff on identifying, prioritizing and testing small herds, and then working with owners to reduce the risk of pathogen spillover. Ó 2016 The Wildlife Society.

Effect of dietary fiber levels on bacterial composition with age in the cecum of meat rabbits

“…may reflect elevated production (Luo et al, 2018). On the other hand, Bibersteinia is an important pathogen that is associated with serious infection (Bleich, Sargeant, & Wiedmann, 2018;Parr, Smith, Jenks, & Thompson, 2018;Heinse, Hardesty, & Harris, 2016) and is implicated in the high incidence of diarrhea in Diet D at 52 days.…”

Pneumonia in bighorn sheep: Risk and resilience

“…More work is needed to assess the strengths and weaknesses of existing approaches and to devise new and better strategies for managing both domestic and wild sheep to reduce transmission risk. Efforts are currently underway to investigate the feasibility of developing and maintaining M. ovipneumoniae ‐free domestic flocks, which could help reduce the significant risk of pathogen transmission from small domestic sheep and goat herds on private lands (Sells et al , Heinse et al , Cassirer et al ).…”

Ecotypic variation in population dynamics of reintroduced bighorn sheep

“…Bronchopneumonia of bighorn sheep is associated with several bacterial pathogens, including M. ovipneumoniae, Mannheimia spp., and Bibersteinia spp. (Cassirer et al , Dassanayake et al , Heinse et al , Wood et al ). The etiology of the disease is complex and typically involves the presence of M. ovipneumoniae (Besser et al ).…”

“…Those inholdings, and private land adjacent to federal land occupied by bighorn sheep, remain problematic (U.S. Fish and Wildlife Service , Clifford et al ; Appendix A) in the context of disease transmission (Heinse et al ) given the metapopulation structure of bighorn sheep (Schwartz et al ; Bleich et al , ).…”

“…As a result, managers should not always anticipate potential benefits associated with the use of similar ecotypes if mitigating circumstances exist. A management strategy that emphasizes zero contact between domestic sheep and bighorn sheep, even if prior exposure has occurred (Cassirer et al ), is most apt to ensure the persistence of bighorn sheep across the landscape (WSWG , Brewer et al ), and there is evidence an informed public is willing to cooperate in such efforts (Heinse et al ).…”