title: Evaluation of equine breeding farm characteristics as risk factors for development of Rhodococcus equi pneumonia in foals.
abstract: OBJECTIVE
  To identify farm characteristics as risk factors for the development of Rhodococcus equi pneumonia in foals.
  
  
  METHODS
  Prospective matched case-control study.
  
  
  METHODS
  2,764 foals on 64 equine breeding farms with 9,991 horses.
  
  
  METHODS
  During 1997, participating veterinarians completed paired data collection forms, 1 for a farm with > or = 1 foal with R equi pneumonia and 1 for an unaffected control farm. Matched data were compared by use of conditional logistic regression analysis.
  
  
  RESULTS
  Farm characteristics found in bivariate analyses to be associated with increased risk for pneumonia caused by R equi in foals included > 200 farm acres, > or = 60 acres used in the husbandry of horses, > 160 horses, > or = 10 mares housed permanently on the farm (resident mares), > 17 foals, > 0.25 foals/acre, and the presence of transient mares (mares brought temporarily to the farm for breeding or foaling) and their foals. Affected farms were significantly more likely to be > 200 acres in size and have > or = 10 resident dam-foal pairs, whereas control farms were significantly more likely to have > or = 75% of their dam-foal pairs housed permanently on the farm.
  
  
  CONCLUSIONS
  Breeding farms with large acreage, a large number of mares and foals, high foal density, and a population of transient mares and foals are at high risk for foals developing pneumonia caused by R equi.
authors.affiliation: Department of Large Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843-4475, USA.
authors.forename: M Keith
authors.initials: MK
authors.lastname: Chaffin
authors.forename: Noah D
authors.initials: ND
authors.lastname: Cohen
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Martens
mesh_terms: D000193:Actinomycetales Infections / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*; D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D000831:Animals, Newborn; D016022:Case-Control Studies; D005260:Female; D006734:Horse Diseases / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D006736:Horses; D016015:Logistic Models; D008297:Male; D018410:Pneumonia, Bacterial / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*; D011156:Population Density; D011446:Prospective Studies; D016929:Rhodococcus equi / Q000276:immunology / Q000472:pathogenicity*; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology