Metritis is among the most common and important diseases that strike the dairy farm. While there are many effective treatment options available, cows with even mild cases pay a considerable price during their lactation period through decreased milk production and reproductive efficiency.
Therefore, it is essential that farmers work with their veterinarians on the treatment, detection and prevention of metritis well before the clinical signs begin.
“The disease we’re talking about is [the] systemic illness of fresh dairy cows, typically in the first 10 days to two weeks after calving,” Dr. Stephen LeBlanc, University of Guelph, explained in a recent DAIReXNET webinar. According to him, the two key symptoms used to define and diagnose metritis are a foul-smelling, fetid vaginal discharge accompanied by a fever.
In his webinar, LeBlanc outlined four major components of metritis that herd managers should consider when discussing the herd health plan with their veterinarian:
- Risk factors
The most obvious factors drastically increasing a cow’s susceptibility to metritis, such as a difficult calving, retained placenta and multiple births, have specific causes stemming well before delivery. A research study done at the University of British Columbia followed a group of 80 cows and observed their dry matter intake before and after calving.
The study found that the cows that contracted metritis had the lowest intake during both the post- and prepartum periods. These animals were eating significantly less about two weeks before the clinical signs actually occurred, signaling early immune and metabolic changes.
“The point is: Metritis is not just a disease of a difficult calving,” LeBlanc said, “but, in fact, has its roots quite a distance before that.” The cows that initially had the lower dry matter intake tended to be the more socially submissive animals in the herd, being pushed out and not able to consume as much at peak feeding times.
LeBlanc suggested providing additional bunk space to accommodate these socially weaker individuals.
Research has shown some strains of E. coli, a major metritis pathogen, are specifically adapted to the uterine environment. Among other pathogens found in the barn, E. coli is universal, and nothing can be done to completely eliminate it from the environment.
“All cows go through some degree of uterine contamination after calving,” LeBlanc said. “Not all bacteria that may contaminate the uterus are created equal … probably the greater importance is the cow’s response to the inevitable contamination.”
He referred to a study done by Doug Hammond at Utah State University which found that the cows that developed metritis showed a significantly lower immune function prior to calving than the cows that remained healthy. Another study linked suboptimal levels of blood calcium, an important nutrient for cell immunity, to cows at a higher risk of infection.
“Even though our working definition of metritis seems pretty simple and straightforward,” LeBlanc said, “its repeatability and precision is not fabulous.” He referred to a study in Germany that surveyed 15 veterinarians and final-year vet students evaluating six discharge samples. Each participant was asked to disclose which samples they believed were from healthy and sick animals.
The results showed only a moderate consistency of opinion among individuals who were all using the same diagnosis criteria.
Additionally, LeBlanc noted that what defines a “fever” can fluctuate based on a lot of situations, especially in the postpartum. He recommends that high temperatures be taken into context before being automatically correlated with a fever.
LeBlanc referenced two large studies of 406 and 982 cow herds comparing the treatment of Ceftiofur and Ampicillin with negative control groups. He noted that the cure rate at seven to nine days post-treatment of either drug was only around 75 percent, indicating how antibiotic treatment has considerable room for further improvement. In fact, he believes some sub-groups may not benefit from any treatment at all. Down the road, he anticipates there being more selection for treating specific individuals.
Another research study on a 110-cow Florida herd showed that Ampicillin and Ceftiofur had the same prevalence at 30- and 60-day first-service A.I. conception rates. In organic operations, there seems to be more variance among therapies.
One study was done on a large organic herd in Texas comparing the solution UterFlush with iodine flushing. Overall, UterFlush had the notably higher cure and first breeding conception rates than iodine and water flushing.
LeBlanc recommended that cows with at least two clinical symptoms, mainly a fetid discharge accompanied by a fever, be treated with an approved drug such as Ceftiofur or any penicillin. He believes taking this course of action, based on the evidence from current studies, is a very judicious decision expected to yield the best results.
Looking to the future, there is an emphasis for more accurate diagnosis and selectiveness of treating animals.
“We do need to build a better evidence base around which cows, with which exact clinical criteria and signs, are good candidates to benefit from the therapies we have available,” LeBlanc said. “In terms of welfare, the performance of the cattle, farm economics and ultimate prevention of development of microbial resistance as we make thoughtful choices about when and how to use antibiotics to treat food animals.”
Jaclyn Krymowski is a student at Ohio State University studying animal science and agricultural communications.