title: Clinical characteristics, prevalence, influence on sow performance, and assessment of sow-related risk factors for granulomatous mastitis in sows.
abstract: OBJECTIVE
  To determine the prevalence and clinical appearance of granulomatous mastitis in sows, to identify sow-related risk factors for development of granulomatous mastitis, and to explore the manner in which the disease influences sow performance.
  
  
  METHODS
  1,254 sows from 76 herds.
  
  
  METHODS
  A clinical examination was performed at time of weaning and 7 days later. In addition, some sows were reexamined at time of weaning in the subsequent lactation. Data were collected on sow performance.
  
  
  RESULTS
  At time of weaning, 205 of 1,254 (16%) sows had granulomatous mastitis, and 7 days later, the prevalence was 19%. Variation between herds was large (0 to 50%). In most of the affected sows (156/205 176%]), only 1 mammary gland was affected. Parity, duration of lactation, and number of teat wounds were identified as risk factors for development of the disease. In 264 of 559 (47%) sows (38/104 [37%] mammary glands), a granuloma recurred in the subsequent lactation. Risk for recurrence was related granuloma appearing in multiple form but not to granuloma size. Affected glands were less distended in the subsequent lactation, suggesting lower milk production. Litter size appeared to be negatively affected by the disease.
  
  
  CONCLUSIONS
  Granu lomatous mastitis is a common disease in sow herds maintained on straw bedding and in group housing, and it has negative effects on sow productivity. A thorough description of the clinical appearance of the disease and the identification of risk factors should contribute to development of relevant control measures.
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Hultén
authors.forename: Arne
authors.initials: A
authors.lastname: Persson
authors.forename: Lena
authors.initials: L
authors.lastname: Eliasson-Selling
authors.forename: Eva
authors.initials: E
authors.lastname: Heldmer
authors.forename: Maria
authors.initials: M
authors.lastname: Lindberg
authors.forename: Urban
authors.initials: U
authors.lastname: Sjögren
authors.forename: Christina
authors.initials: C
authors.lastname: Kugelberg
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Ehlorsson
mesh_terms: D000818:Animals; D002908:Chronic Disease; D005260:Female; D006099:Granuloma / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology* / Q000662:veterinary*; D007774:Lactation; D008098:Litter Size; D008321:Mammary Glands, Animal / Q000473:pathology; D008413:Mastitis / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology* / Q000662:veterinary*; D015995:Prevalence; D012008:Recurrence; D012307:Risk Factors; D012867:Skin / Q000473:pathology; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000503:physiopathology*; D014947:Wounds and Injuries / Q000150:complications