Liver abscesses are formed by pathogenic toxins that have escaped the rumen
When the rumen wall is damaged by the effects of acidosis, bacteria can enter the bloodstream and proliferate throughout the liver (Galyean M. L. and Rivera J. D. 2003).
- The most common causative agents are: Fusobacterium necrophorum (100% of cases) and Arcanobacter (now Trueperella) pyogenes (35% of cases).
- Both are part of the normal microbiota found in the rumen.
- Toxins produced by these bacteria lead to a coagulative necrosis that develop into encapsulated abscesses over time and the form of a fibrous scar (up to 15cm in size).
FAQ About Cattle Liver Abscess
Liver abscesses are primarily caused by Fusobacterium necrophorum, found in 100% of cases, and Arcanobacterium (Trueperella) pyogenes, found in about 35% of cases. These bacteria are part of the normal rumen microflora but can become pathogenic when the rumen wall is damaged, often due to acidosis from high-grain diets.
When the rumen wall is compromised—typically due to subacute ruminal acidosis (SARA)—bacteria can translocate into the portal bloodstream and reach the liver. There, they cause coagulative necrosis, which evolves into encapsulated abscesses
Most liver abscesses are subclinical, meaning they show no obvious symptoms. However, affected animals may exhibit:
- Reduced feed intake
- Lower weight gain
- Decreased milk production
- In severe cases, signs of systemic illness or sudden death due to complications like caudal vena cava thrombosis.
Prevention focuses on maintaining rumen health:
- Avoid sudden dietary changes
- Limit high-starch, low-fiber diets
- Use feed additives like buffers or probiotics such as live yeast
- Implement proper bunk management
- Consider vaccination strategies in high-risk herds
Liver abscesses are a significant concern in the beef industry, with varying prevalence rates depending on factors such as diet and management practices. Here are some key points:
- Prevalence rate: The prevalence of liver abscesses in feedlot cattle can range from 12% to 32%, depending on the region and feeding practices
- Economic impact: Liver abscesses result in substantial economic losses, including reduced feed efficiency, increased carcass trimming, and liver condemnation
- Regional variations: Different regions may experience varying rates of liver abscesses due to differences in feedstuffs, management practices, and cattle types