Evaluation of equine breeding farm management and preventative health practices as risk factors for development of Rhodococcus equi pneumonia in foals

Objective-To determine whether foal management practices, environmental management, and preventative health practices are risk factors for development of Rhodococcus equi pneumonia in foals. Design-Prospective matched case-control study. Animals-2,764 foals on 64 equine breeding farms with 9,991 horses. Procedure-During 1997, participating veterinarians completed paired data collection forms for comparison; 1 for an affected farm (containing greater than or equal to 1 foal with pneumonia caused by R equi) and 1 for a control farm. Information collected pertained to stabling facilities, environmental management, foal husbandry, and preventative equine health practices. Results-Matched farm data compared by use of conditional logistic regression indicated that personnel on affected farms were more likely to attend foal births, test foals for adequacy of passive immunity, administer plasma or other treatments to foals to supplement serum immunoglobulin concentrations, administer hyperimmune plasma prophylactically to foals, vaccinate mares and foals against Streptococcus equi infection, and use multiple anthelmintics in deworming programs. Affected farms were also more likely to have foals that developed other respiratory tract disorders and were approximately 4 times as likely to have dirt floors in stalls used for housing foals as were control farms. Conclusions and Clinical Relevance-Rhodococcus equi pneumonia does not appear to be associated with poor farm management or a lack of attention to preventative health practices. Housing foals in stalls with dirt floors may increase the risk for development of R equi pneumonia.