In which condition might clinical signs include lethargy and generalized edema?

The condition characterized by clinical signs of lethargy and generalized edema is indeed Carp edema virus (CEV) infection. This viral infection affects cyprinid fish, including carp, and is known for causing significant swelling, particularly in the abdominal area, leading to generalized edema. The lethargy observed in infected fish is a reflection of overall health deterioration, often due to the stress of the infection and the impacts it has on their physiological functioning.

In this context, generalized edema results from fluid accumulation within the tissues, a hallmark of the infection. CEV disrupts normal cellular processes and can lead to inflammation and fluid imbalance in the affected fish.

While other conditions can present with various symptoms, they do not specifically match the combination of lethargy and generalized edema as clearly as CEV does. For instance, Myxobolus infections often lead to specific tissue lesions and may not commonly present with generalized edema. Velvet disease, caused by the parasite Oodinium, typically presents with signs such as discoloration and excess mucus, while Renibacterium infection can cause lethargy but is more associated with abscess formation rather than generalized edema.

Overall, CEV is distinctly associated with these specific clinical signs in affected fish populations, making it