Mycoplasma Strains

Project Title

Survey of Mycoplasma Bovis Strains Derived from Calves in Commercial Feedlots in Western Canada


Dr. Murray Jelinski

Murray Jelinski, DVM, John Campbell, DVM (Western College of Veterinary Medicine), Andrew van Kessel, PhD (University of Saskatchewan)

Status Project Code
Completed March, 2010 0007-055


Mycoplasma bovis has become a significant bacterial pathogen in commercial feedlots over the past decade.  Since Mycoplasma bacteria lack a cell wall, antibiotics (which disturb bacterial cell walls) are not very effective for treating cattle infected with these bacteria.  M. bovis is involved in bovine respiratory disease complex (BRD), and also plays a role in chronic pneumonia and polyarthritis syndrome (CPPS) in high-risk fall-placed feedlot calves.  This syndrome has emerged as a leading cause of mortality in feedlot calves in Western Canada.  Calves with CPPS may also be euthanized due to severe lameness problems.  The disease is quite complex, as there are many different strains of M. bovis, and although many calves become infected, not all become sick, and not all develop CPPS. 


  • determine the prevalence of Mycoplasma bovis in fall-placed feedlot calves;
  • describe the ecology of M. bovis within pens of feedlot calves; and
  • determine if specific strains of M. bovis are related to disease in the feedlot.