Table 6.
Cause-of-death and diagnostic case definitions for infectious causes of bovine perinatal mortality
| Cause-of-death | Sub-category | Case definition | Diagnostic criteria |
|---|---|---|---|
| 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. |