Clinical characteristics, prevalence, influence on sow performance, and assessment of sow-related risk factors for granulomatous mastitis in sows.
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.
Hultén
Fredrik
F
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Persson
Arne
A
Eliasson-Selling
Lena
L
Heldmer
Eva
E
Lindberg
Maria
M
Sjögren
Urban
U
Kugelberg
Christina
C
Ehlorsson
Carl-Johan
CJ
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