Foal-Level Risk Factors Associated With Development of Rhodococcus equi Pneumonia at a Quarter Horse Breeding Farm

Rhodococcus equifoal pneumonia: Update on epidemiology, immunity, treatment and prevention

“…Consequently, some veterinarians transfuse foals with 2 L of plasma to horse foals 24 to 36 h after birth (approximately 40 mL/kg). [171][172][173] Results of 2 retrospective cohort studies indicate that foals transfused with 2 L of R. equi hyperimmune plasma were significantly less likely to develop either subclinical 172 or clinical 173 R. equi pneumonia than foals transfused with 1 L of plasma. Because of the limitations of observational studies, well-designed clinical trials are needed to determine the relative efficacy of transfusing 2 L vs. 1 L. Recently, higher serum antibody activities in hyperimmune plasma against either VapA or PNAG were demonstrated to be associated with protection against rhodococcal pneumonia in foals at two large breeding farms in the US.…”

“…Although transfusion of 2 L appears safe, [171][172][173][174] efforts to develop alternative approaches to passive immunisation (e.g. concentrated antibody products) are needed to improve convenience and safety of passive immunisation of foals to control R. equi pneumonia.…”

“…Chemoprophylaxis with antimicrobial agents has been investigated for preventing R. equi pneumonia in foals, 17,37,55 but this practice is strongly discouraged because widespread antimicrobial use selects for resistant strains of R. equi. 45,50 Although various management practices and environmental conditions have been associated with increased odds of pneumonia attributed to R. equi at farms, 1,2,5,10,[169][170][171] randomised, controlled trials documenting efficacy of management strategies such as increasing grass cover, reducing population density, removing faeces from paddocks, and foaling at pasture, have not been reported to the authors' knowledge.…”

Randomized, controlled trial comparingRhodococcus equiandpoly‐N‐acetyl glucosamine hyperimmune plasma to preventR equipneumonia in foals

“…Although many organisms cause respiratory disease in foals, Rhodococcus equi is considered the most common cause of severe pneumonia. 1 , 2 , 3 Rhodococcal pneumonia is important to the equine industry because it is endemic at many horse‐breeding farms (with cumulative incidence often exceeding 20%‐40% of the foal population), 4 , 5 , 6 , 7 where the costs resulting from veterinary care, long‐term treatment, and mortality of some foals can be very high. 8 In addition to substantial immediate costs, R equi pneumonia has a long‐term detrimental effect on the equine industry because foals that recover from the disease are less likely to race as adults.…”

“… 15 , 27 , 29 , 30 , 31 This variable clinical efficacy is likely explained in part by variation in the activity of antibodies recognizing R equi among plasma products, 32 differences in volume of plasma transfused to foals, 29 , 30 interindividual variability in susceptibility to infection, and variation among veterinarians in criteria for diagnosis of R equi pneumonia. 2 , 4 , 7 , 8 , 9 , 10 , 12 , 14 , 15 , 19 , 27 , 29 , 30 , 33 …”