|
|
Introduction: Necropsy is the systematic examination of an animal carcass performed in such a manner that it allows for the discovery and characterization of lesions. It is the equivalent in human medicine of an autopsy. Necropsy also allows for the systematic collection of specimens. |
Indications for performing a necropsy: Depending, of course, on the wishes of the owner:
In every situation in which an animal dies and the cause of death is unclear.
When it will help determine the cause of disease in a herd or flock, thereby allowing for appropriate treatment and prevention for the health of the remaining animals.
When it will allow for the collection of samples necessary for diagnosis or for ruling out important DfDx's. These samples may not be accessible (at least economically) by any other means.
A necropsy is an opportunity to learn. By visualizing and understanding the lesions present in an animal, a veterinarian can also understand how they produced the clinical signs observed. In this manner, the veterinarian will be better prepared when he or she deals with the next, similar case.
A necropsy should involve:
1. Identification and characterization of Gross Lesions
2. Collection of specimens
for further examination. Exactly what samples are collected and
submitted
will depend on the Differential Diagnoses in the case. Some example
procedures
performed on specimens
are:
- histopathology (microscopic examination of tissue)
- bacterial or fungal culture
- viral isolation
- identification in tissue of foreign antigen or DNA
(by immunohistochemistry or PCR,
respectively)
- parasite identification
- assay of tissue for toxins or nutrients (e.g. selenium)
Remember:
Specimens must be collected and submitted APPROPRIATELY or they may not result in interpretable results.
The mere presence of certain infectious agents, especially by extremely sensitive methods like PCR, does not always mean it was the cause of the clinical problems. Diagnostic findings must be correlated with appropriate clinical signs and the nature of the lesions present.
The Test: There are many ways to perform a necropsy, and the method used
depends on several factors.
|
First year pathology resident, Jennifer Johnson, performs a necropsy on a horse. Necropsy of large animals requires adequate space to ensure a thorough examination. |
It is important to be thorough and systematic so no lesions go unnoticed. For a diagnosis to be reached, it is essential to have an understanding of the types of tissues to be collected, to know the amount of tissue needed to perform appropriate tests, and how to properly store the tissues. Diagnostic lab personnel are more than happy to give the veterinarian guidelines on these matters.
|
It is important to have all the appropriate equipment necessary to perform the necropsy as well as the supplies needed for proper collection of tissue samples.
|
Basic Necropsy Equipment
|
Several types of necropsies can be performed, and the situation will dictate the extent of the investigation. Regardless of the type of necropsy performed, the basic tools necessary remain the same. Protective clothing is also important and should include at least coveralls, shoe covers/rubber boots, and gloves. In cases where zoonotic disease is suspected or a possibility, extra caution should be taken to ensure all personnel are properly protected.
For more information...
