Autopsy and specimen requirements and expectations
In a disease outbreak sacrifice of a severely affected individual can provide the information needed to treat the others. Autopsy examinations of any fish dying unexpectedly in a pond is best practice to identify any endemic pathogens present.
As fish start to decompose very quickly, an autopsy examination is most useful when performed on a freshly euthanized fish or within one hour of death. Parasitic disease will not be identified if the fish has been dead in the pond for some time as the internal organs decay rapidly. Live fish for post mortem examinations can be transported chilled to the clinic.
A gross autopsy is the visual examination of all the internal and external structures for abnormalities. It is usually important that samples are collected for diagnostic tests unless the cause is found during the autopsy. Skin scrapes, fin and gill clips should be obtained if not already done. Kidney cultures are routinely collected. Any lesions found should have samples taken for cytology, culture and histology as appropriate. Tissue sampling for histopathology, virus isolation, toxicology, electron microscopy, etc. is collected as required.
Afterwards when the autopsy examination is completed the results are discussed with the owner and further testing of any of the collected samples considered relative to their potential usefulness and to their cost.