Metritis is an inflammation of the uterus that occurs in cows shortly after they give birth. The condition is most commonly seen within the first 10 days post-calving but can arise up to 21 days later. It is a costly issue affecting dairy and beef cattle operations worldwide. The incidence rate in dairy cows ranges from 15% to 20%, though on some farms it can affect up to 40% of the herd.
Causes and Risk Factors
Metritis is a bacterial disease. Following calving, some bacterial contamination of the uterus is common. Whether this contamination progresses to a clinical infection depends on the cow’s immune response and the types of bacteria present. Research has shown the development of metritis is associated with a shift in the uterine microbiome, with higher amounts of bacteria from the Bacteroidetes and Fusobacteria phyla. Specific pathogens such as Escherichia coli and Trueperella pyogenes are strongly linked to the disease.
Several factors can increase a cow’s susceptibility by compromising her uterine defenses. A primary risk factor is a retained placenta, also known as retained fetal membranes. Difficult calving, or dystocia, which can cause trauma to the reproductive tract, also elevates the risk. Other contributing events include stillbirths and twin births.
Metabolic stress during the transition period is another predisposing factor. Conditions like subclinical hypocalcemia (low blood calcium) and ketosis weaken the cow’s immune system. Reduced feed intake before calving can also suppress immune function, making it harder for the cow to clear the bacterial contamination that occurs after birth.
Clinical Signs and Diagnosis
The most prominent sign of metritis is a watery, reddish-brown uterine discharge with a foul smell. The uterus will also be abnormally enlarged. Cows with metritis also frequently exhibit systemic signs of illness, including a fever over 39.5°C, decreased milk production, lethargy, and a loss of appetite. The changes in activity patterns can be more pronounced in first-time calving cows compared to older ones.
A veterinarian confirms a diagnosis through a physical examination. This process may involve rectal palpation to assess the size and condition of the uterus. A vaginoscope may also be used to visually inspect the vagina and the nature of the discharge.
Treatment Approaches
The standard treatment for metritis, particularly when the cow shows systemic signs of illness, is the administration of systemic antibiotics. This approach is favored because the infection affects the entire body. While intrauterine infusions of antibiotics were once common, their effectiveness is now debated, and systemic therapy is preferred for its reliability.
Supportive care is also an important component of the treatment plan. Non-steroidal anti-inflammatory drugs (NSAIDs) are often administered alongside antibiotics to reduce the cow’s fever, alleviate pain, and improve her comfort and appetite. Studies have shown that using NSAIDs can improve reproductive outcomes in affected cows. For animals that have become dehydrated, fluid therapy may also be necessary.
Preventative antibiotic treatment for cows with retained fetal membranes has not been shown to be effective; treatment is focused on cows that develop clinical signs of metritis.
Prevention Through Herd Management
Preventing metritis revolves around management strategies that minimize risk factors. A primary step is providing a clean, dry, and spacious calving environment. This reduces the bacterial load that cows are exposed to during and after giving birth. The calving area should be separate from pens housing sick animals to limit exposure to pathogens.
Proper nutrition during the transition period is another key element of prevention. A well-formulated diet helps prevent metabolic diseases like hypocalcemia and ketosis. Management practices that optimize comfort, such as providing adequate bunk space and heat abatement, are used to encourage feed consumption and support a robust immune system.
Careful supervision of the calving process is also beneficial. Having clear protocols for when and how to assist with a difficult birth can minimize trauma to the cow’s reproductive tract. For cows that experience a high-risk event, such as a retained placenta or twins, a specific management plan should be in place, including close monitoring for the early signs of metritis.
Impact on Fertility and Profitability
Metritis directly impacts a farm’s profitability through decreased fertility and productivity. The inflammation caused by the infection can damage the lining of the uterus, impairing the cow’s ability to conceive. This leads to several negative reproductive outcomes:
- A longer interval before the cow can be successfully re-bred
- An increase in the number of inseminations required for conception
- A higher likelihood of being culled from the herd due to infertility
- Reduced calf production
The economic losses from a single case of metritis include both direct and indirect costs. Direct costs include expenses for veterinary services and medications. Indirect costs are often more substantial and include lost revenue from decreased milk production during the illness.
The average total cost of one case of metritis is estimated to range from €106 to €490. This financial toll is compounded by the potential costs associated with replacing a culled animal. Effective prevention and treatment are therefore important for managing the disease’s economic impact.