Sheep Producers Should Ask Questions when being Contacted About Possible Domestic/Bighorn Sheep Health Issues

As research continues into domestic and bighorn sheep conflicts and the industry seeks resolution to the underlying cause of the issue, producers may be contacted by researchers and others. In order to best aid in achieving collaborative solutions to understanding bighorn health issues, producers should ask the following questions provided by Drs. Margaret Highland and Don Knowles if contacted:

• Animal's home range location (for bighorn herds, include anything that would identify the herd, such as location or herd name, if applicable). How many bighorn sheep are radio-collared in each herd?
• How many bighorn sheep are currently in each herd, what is the ewe:ram ratio?
• List dates of all capture events (specify herd, reason for capture, how many captured).
• List of all medications/drugs given at time of capture, particularly if steroids (ie. dexamethasone) was administered and whether the capture was by tranquilization or net capture.
• Translocations either in or out of each herd, include number of bighorn sheep moved in/out
• All results from microbial screenings for bighorn sheep herds, including Mycoplasma ovipneumoniae and Pasteurellaceae spp. (include dates of sample collection)
• Overall health of bighorn sheep herd
  • Dates (beginning to end) of respiratory disease and/or die-off events that have occurred since herd was established (include number of animals involved, number of deaths).
  • lamb recruitment each year since herd was established (lambs born versus number that live to be 1 year old)
• Date and cause of death for each deceased bighorn sheep; number of bighorn sheep affected (this should include non-respiratory disease causes)
• Other environmental factors
  • Hunting (number and age of bighorn killed, date killed, and number of bighorn sheep in the herd at the time of hunt)
  • Non-human predation
  • Feeding stations bighorn sheep use and what other wildlife species observed at stations
• Dates of all reported (observed) contacts between domestic small ruminants and bighorn sheep

These questions are important and relevant to understanding the overall health of bighorn sheep, a big part of which includes the environment in which they live and physiological stressors that are imposed upon them. As domestic livestock producers well know, disease problems are caused by more than just the presence of this or that possible pathogen, but rather the environment in which the animal is in can be just as important in determining how well the animal copes with exposure to, or infection with, pathogens. Disease occurs when ALL THREE of the following fundamental components unfortunately come together: the host (must be susceptible), the environment (stressors due to human impact or other environmental factors), and the pathogen (dose or amount of exposure, virulence). Focusing on just one aspect of disease will not solve any complex disease problem, which is exactly what bighorn sheep pneumonia is, a complex problem that is remains incompletely understood.

If you are contacted, please feel free to contact ASI for additional resources or background at (303) 771-3500.