A cow that has recently undergone multiple flushings presents with a high temperature and renal issues. What is the most appropriate course of action?

In this scenario, the cow has a high temperature and renal issues following multiple flushings, which raises concerns about possible complications such as infection or damage to the kidneys. Given these symptoms, addressing the underlying renal issues is critical, especially if there is a significant risk to the cow's health.

Surgical removal of the affected kidney is the most appropriate course of action because it can provide a definitive treatment solution when there's a serious renal condition that is not resolving on its own. If the kidney is severely compromised, leaving it in place could lead to systemic infection, pain, and further deterioration of the cow's health. By removing the affected kidney, you not only alleviate ongoing health risks but also help in managing the cow's temperature and overall condition more effectively.

Choosing to begin extensive fluid therapy may provide temporary support but doesn't address the root cause of the renal issue. Evacuating the urinary bladder could be relevant if there's an obstruction, but it does not address potential kidney damage or infection. Assuming the condition is self-limiting is not appropriate given the clinical signs presented, as this approach could lead to exacerbation of the cow's health status. Thus, surgical intervention is necessary to provide a long-term solution to the problem at hand.