Brandi L. Felts
E. Frances Cassirer
Jonathan A. Jenks
Daniel P. Walsh
Thomas E. Besser
Logan K. Weyand
2025
<p><span>We hypothesized that bighorn sheep ewes with chronic nasal </span><i>Mycoplasma ovipneumoniae</i><span> carriage are the source of infection that results in fatal lamb pneumonia. We tested this hypothesis in captive bighorn ewes at two study facilities over a 5-year period, by identifying carrier ewes and then comparing lamb fates in groups that did (exposed pens) or did not (non-exposed pens) include one or more carrier ewes. Most (23 of 30) lambs born in exposed pens, but none of 11 lambs born in non-exposed pens, contracted fatal pneumonia. In addition, surviving lambs in exposed pens showed obvious signs of respiratory disease while lambs in non-exposed pens did not. In crossover experiments, individual non-carrier ewes had lambs that experienced fatal pneumonia in years when housed in exposed pens, but not in years when housed in non-exposed pens. The results of these studies clearly associate lamb pneumonia to exposure to </span><i>M. ovipneumoniae</i><span> carrier ewes, consistent with a necessary role for this agent in epizootic pneumonia of bighorn sheep. These data specifically highlight the role of chronic </span><i>M. ovipneumoniae</i><span> carriage by some bighorn ewes in the epidemiology of this population-limiting wildlife disease.</span></p>
application/pdf
10.1128/jcm.01328-24
en
American Society for Microbiology
Fatal interactions: Pneumonia in bighorn lambs following experimental exposure to carriers of Mycoplasma ovipneumoniae
article