Table 6 Cause-of-death and diagnostic case definitions for infectious causes of bovine perinatal mortality

Infection

Foetopathogenic bacteria

Infection with a significant bacterium: Bacillus licheniformis, Campylobacter foetus, Listeria monocytogenes, Salmonella Dublin, Trueperella pyogenes, etc

Pure heavy growth in culture of pathogenic species from abomasal contents/foetal tissues or nearly pure/mixed growth with associated lesions consistent with foetal sepsis/placentitis (in particular for potential contaminants, e.g. E. coli). If isolated from placenta only, associated intra-lesional bacterial placentitis.

Chlamydophilia/Parachlamydiacae

Detection of organism in the placenta, foetal tissue or abomasal contents (e.g. MZN smear, PCR, IHC) confirmed by histopathology

Coxiella burnetii

Detection of organism in the placenta, foetal tissue or abomasal contents (e.g. MZN smear, PCR, IHC) confirmed by histopathological lesions (e.g. necrotising placentitis); Detection of the organism in the absence of lesions indicates very acute recent infection.

Leptospira spp (e.g. Hardjo, Grippotyphosa, Australis)

Detection of pathogenic antigen (e.g. PCR/FAT/IHC-positive) in foetal tissues (e.g. kidney, spleen) with accompanying lesions or detection of high foetal antibody titre indicating recent infection

Foetopathogenic fungi

Aspergillus app, zygomycetes, yeasts, etc

Detection of fungal hyphea in abomasal contents/placenta (e.g. wet prep, culture) with associated gross/histopathology lesions (e.g. foetal dermatitis, IUGR, placentitis, hepatomegaly)

Foetopathogenic parasite

Neospora caninum

Detection of histological lesions (characteristic neuropathology, myocardial necrosis, multifocal placentitis; cause) and the parasite antigen in foetal tissues (e.g. PCR; infection) +/− foetal antibodies (exposure)

Foetopathogenic viruses

BoHV-I, 4

Detection of viral antigen in foetal tissues (e.g. liver, spleen, adrenal) +/− lesions, e.g. focal necrotising hepatitis, placentitis

BVDv

Detection of viral antigen in foetal tissues (e.g. spleen, thymus, adrenal, ear) and gross/histopathology lesions

SBV

Detection of two or more syndromic gross lesions (arthrogryposis, hydranencephaly, torticollis, scoliosis, kyphosis, brachygnathia inferior) and foetal antigen (e.g. PCR).

Infectious lesions

Compelling lesions indicative of infection

Gross/histological lesions consistent with exposure/response to infection e.g. pericarditis, meningoencephalitis, enteritis omphalo-peritonitis, pleuropneumonia, lymphadenomegaly, systemic sepsis (lesions in at least two organs) and placentitis.