The distinction between pneumonia caused by R. equi and that caused by other bacterial pathogens in important because the treatment approaches are different. Although time consuming to administer and expensive to produce or buy, this is the single most cost-effective measure to prevent the disease on farms with a high incidence of R. equi pneumonia. Active immunization It would be considerably more convenient to control R. equi pneumonia on enzootically infected farms by the active immunization of mares and their foals with a protective antigen rather than by the intravenous administration of a large volume of plasma. Such experimental attempts have been generally unrewarding and vaccines against R. equi infections are not currently available. Clearly, R. equi can be a devastating and demoralizing problem on some horse farms.
Control is possible, but expensive.
It is also crucial that pneumonic foals are not sent to spread infection from enzootic farms to those farms with little contamination. Improved and less expensive control approaches in the long term will depend on a better understanding of why this disease attacks the young foal. Dr. Steve Giguerr is a graduate research assistant in the Department of Pathobiology at the Ontario Veterinary College, University of Guelph, Ontario, Canada. He presented his findings during the 1997 AAEP Convention in Phoenix, Arizona.