Question

The image shows an infarct in the liver discovered on post mortem exam of a mature beef cow which died one hour before in a western mountain pasture, after being observed to appear normal one day earlier. There is also dark red urine in the bladder. The pasture contains native plants, some pine trees, and a marshy area with water plants. The cows are unvaccinated and were never wormed. Given this history and the lesion found, the most likely cause of death is

Blue-green algae toxicity
Death camas toxicity
Bacillary hemoglobinuria
Viral hepatitis
Pine needle poisoning

Answer 1

The most likely cause of death in the described scenario is bacillary hemoglobinuria, a clostridial disease, suggested by the liver infarct and dark red urine.

Step-by-step explanation:

Given the history and lesion found during the post mortem examination of the beef cow, the most likely cause of death in this scenario is bacillary hemoglobinuria, which is a clostridial disease affecting the liver and is often associated with a sudden death syndrome in cattle grazing on certain pastures. Bacillary hemoglobinuria is caused by Clostridium haemolyticum, which thrives in low-oxygen environments such as those created by liver damage, like an infarct. The presence of an infarct in the liver and dark red urine in the bladder suggests massive intravascular hemolysis, which is a hallmark of this disease. This condition may not be as well known as other causes such as blue-green algae toxicity, death camas toxicity, viral hepatitis, or pine needle poisoning, which could also affect cattle in similar environments but present with different clinical signs or lesions.