The pathology and weather triggers of acute bovine liver disease
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(Thesis)
Date
2022
Authors
Manthorpe, Eve Marie
Editors
Advisors
Woolford, Lucy
Rawlin, Grant
Jerrett, Ian
Rawlin, Grant
Jerrett, Ian
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Thesis
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Abstract
Acute bovine liver disease is a sporadic hepatic disease affecting cattle in southern Australia, characterised histologically by striking periportal hepatocellular necrosis. The cause of ABLD is currently unknown. We describe the clinical and pathological findings of ABLD in 45 naturally affected cattle from 13 outbreaks occurring from 2010 to 2019 in Victoria, Australia. Clinical signs commonly included a combination of mild photosensitisation, progressive neurological signs, and hypogalactia, which preceded death by 48 hours or less. All affected animals had marked elevations in activities of glutamate dehydrogenase, aspartate aminotransferase, and gamma-glutamyl transferase. At post-mortem, the most common lesions were serosal petechiae and/or gastrointestinal haemorrhage, and hepatomegaly with a pronounced hepatic reticular pattern. The principal histological lesion was widespread, severe periportal hepatocellular coagulative necrosis and erythrocyte pooling— which often extended to massive necrosis. Lesions in other organs were uncommon. Additionally, we describe the geographic and seasonal occurrence, and weather triggers preceding 26 naturally occurring ABLD outbreaks, across 23 properties occurring from 2010 to 2020 in Victoria, Australia. We found a positive correlation between ABLD events and the average daily dewpoint temperature in the 15-days preceding outbreaks, suggesting that dew formation may be a key indicator for disease. Outbreaks occurred in herds located along the southern coastal plain of Victoria, and occasionally within the low-lying regions of the Great Dividing Range and were observed most frequently in autumn to early winter. This provides an initial insight into the ecological aspects of ABLD outbreaks. Notably, our study provides further evidence for involvement of a potent hepatotoxin produced by an agent that requires moisture for proliferation and/or toxin production.
School/Discipline
School of Animal and Veterinary Sciences
Dissertation Note
Thesis (MPhil) -- University of Adelaide, School of Animal and Veterinary Sciences, 2022
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