A retrospective epidemiological analysis of risk factors for a primary necropsy diagnosis of bovine respiratory disease.
Bovine respiratory disease (BRD) is a multifactorial disease and the primary cause of both bovine morbidity and mortality in Ireland. The risk factors associated with a primary necropsy diagnosis of BRD among cattle in the traditional (non-feedlot) husbandry systems prevalent in Ireland have not been investigated previously. The aim of this case-control study was to investigate those risk factors among cattle of all ages over an 8 year period. A total of 3,090 BRD cases and 5,236 controls were matched by submitting veterinary practitioner. Univariable and multivariable analyses were performed to examine the association of selected animallevel, herd-level and environmental risk factors with case or control status using a conditional logistical regression model. Male cattle aged more than 31 days were significantly more likely to record a primary necropsy diagnosis of BRD than female cattle. Older cattle of both sexes were at increased odds of a BRD necropsy diagnosis than younger calves with the exception of female cattle aged greater than 165 days. The risk of a primary necropsy diagnosis of BRD increased with increasing herd size and decreased with increasing time in days since the last animal movement into the submitting herd. There were significantly reduced odds of a primary necropsy diagnosis of BRD in the summer (June to August) when compared with the autumn (September to November). These findings identify significant risk factors for a necropsy diagnosis of BRD under non-feedlot-type husbandry conditions.
Sligo Regional Veterinary Laboratory, Department of Agriculture, Food and Marine, Doonally, Sligo, Ireland. Electronic address: gerard.murray@agriculture.gov.ie.
G M
GM
Murray
UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
J P
JP
Cassidy
Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
T A
TA
Clegg
Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
J A
JA
Tratalos
Irish Cattle Breeders Federation (ICBF), Highfield House, Shinagh, Bandon, Co. Cork, Ireland.
J
J
McClure
Central Veterinary Research Laboratory, Department of Agriculture, Food and Marine, Celbridge, Co. Kildare, Ireland.
R G
RG
O'Neill
Central Veterinary Research Laboratory, Department of Agriculture, Food and Marine, Celbridge, Co. Kildare, Ireland.
D J
DJ
Sammin
Central Veterinary Research Laboratory, Department of Agriculture, Food and Marine, Celbridge, Co. Kildare, Ireland.
M J
MJ
Casey
Central Veterinary Research Laboratory, Department of Agriculture, Food and Marine, Celbridge, Co. Kildare, Ireland.
M
M
McElroy
Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre (AGRIC), Teagasc, Grange, Dunsany, Co. Meath, Ireland.
B
B
Earley
UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
N
N
Bourke
Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
S J
SJ
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D000818:Animals; D001344:Autopsy; D048090:Bovine Respiratory Disease Complex / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D016022:Case-Control Studies; D002417:Cattle; D005260:Female; D007494:Ireland / Q000453:epidemiology; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors
BRD; Bovine; Mortality; Necropsy; Respiratory disease; Risk factors