Data from: Bighorn sheep show similar in-host responses to the same pathogen strain in two contrasting environments

Ecological context – the biotic and abiotic environment, along with its
influence on population mixing dynamics and individual susceptibility –
are thought to have major bearing on epidemic outcomes. However, direct
comparisons of disease events in contrasting ecological contexts in
wildlife systems are often confounded by concurrent differences in host
genetics, exposure histories, or pathogen strains. Here, we compare
disease dynamics of a Mycoplasma ovipneumoniae spillover event that
affected bighorn sheep populations in two contrasting ecological contexts.
One event occurred on the herd’s home range near the Rio Grande Gorge in
New Mexico, while the other occurred in a captive facility at Hardware
Ranch in Utah. While data collection regimens varied between the two
sites, general patterns of antibody signal strength and symptom emergence
were consistent. Symptoms appeared in the captive setting an average of
12.9 days post-exposure, average time to seroconversion was 24.9 days, and
clinical signs peaked at approximately 36 days post-infection. These
patterns were consistent with serological testing and subsequent declines
in symptom intensity in the free-ranging herd. At the captive site, older
animals exhibited more severe declines in body condition and loin
thickness, higher symptom burdens, and slower antibody response to the
pathogen than younger animals.  Younger animals were more likely
than older animals to clear infection by the time of sampling at both
sites. The patterns presented here suggest that environment may not be a
major determinant of epidemiological outcomes in the bighorn sheep - M.
ovipneumoniae system, elevating the possibility that host- or
pathogen-factors may be responsible for observed variation.