Animal Necropsy: Way to find reason of animal death 

What is Necropsy?

Necropsy is a process in which we examine, identify, or search the reason for the death of animals, birds, or another organism except for humans by dissecting the animals are called Necropsy.

What is different b/w Autopsy & Necropsy

Necropsy or Autopsy is the approximately same terms, but little difference in necropsy is often used for non-human animals and autopsy is used for humans. The purpose is almost the same for both terms to identify or determine to reason the death of organisms.

Why Necropsy Needed?

If an animal is dead, we don’t know the cause of death or if the death is suspicious or killed by the disease or any other reason than necropsy is needed. On the other hand, Research purpose and any other infection that led to death that alarm the death of another organism.

Tools required for Necropsy

There are following certain tools used for the purpose of necropsy. 

  • Tissue pincers
  • Bone cutting equipment
  • Mandible Saw

Procedure of Necropsy

There are the following steps of necropsy.


Firstly, you need the permission from owner’s body to dissecting the animal body whether these are animal or human bodies.

Get the History

You get the complete history of dead organisms about the sex, age, and their breeding’s including their diet height and weight, etc.

Outer Investigations

Firstly, after getting information including the history permission about the organism observes or examine the external side of the organism. Examine the skin or tissue damage then write on the page or take a photo of this site or area.

Examine the fesses color their smell or anything present in them such as parasite or blood. Check the age by determining the teeth and check the dehydration by examining the eye sinking.

Open the Body

After the external investigations, the next step is to open the body by placing the animal on the table’s left side for the sake of exposing the internal body organs. Complete the dissection and remove the skin from the animal if you observe the skin is sticky then dehydration takes place. After removing the skin, the next step is exposing the visceral organ from the abdomen.

Remove the muscles from internal organs and cuttings the ribs to expose the complete organ or detach them from the body. Cut the ribs both ventrally and dorsally from the animal. After removing the visceral organ accurately from the body then you note the size position and their color or location of the organ.

Separate the organ

The next step is to separate the organs from the other organs because the examine the organs within the body is tough and difficult work so for this purpose you need to separate the organs. There are Following organs are separate from the other tissue or organs.

  • Tongue
  • Esophagus
  • Brain
  • Reproductive tract
  • Liver
  • Urinogenital tract
  • Intestinal Tract

Separate the organs properly from each other No cut can be taken

Examining the Sample

Now you have a Group of Samples it is time to observe or examine the sample. Examine the Color size weight of the organs and check the color of any fluid present in them. Several Cut made taken for the purpose of tissue samplings.[1] Necropsy_Manual_ZP130193_PrintReady_Zoetis.pdf[2]ZP130193_Necropsy_Manual_US-EN_Zoetis_r1.indd ([3]Microsoft Word – NecropsyGuideline.doc (

Important tissues/ organs to Examine Necropsy

In the process all organs are important but can be examined those organs that are infected, injured or may be reason of death. Organs tissue should be gathered in pairs form because one is treating with formalin for the purpose of histopathology and the other is for the purpose of viruses and bacterial culture. The following tissue should be necessary for the purpose of examination.

  • Spleen
  • Heart
  • Kidney
  • Liver
  • Lung
  • brain
  • Intestine

Some necessary things should be your mind not to crush any organs or tissue while sampling or don’t they use the hard cutter or anything that destroy the sampling.


The spleen would be Moderately smooth, not pompous, and not rupture

When doubled. On cut external, it must be unbroken.

Lymph nodes

Lymph nodes have normal their own positions and homogenous white color and mesenteric lymph have the same dark pigment that shows the normal ruminants.


Usually, the brain is cut down proportionally down to the halves and treated with formalin to examining.


The heart now can be observed to examine the fluid or blood present in the heart by cutting their chambers. It is difficult to examine the chambers of the heart. Firstly, you cut the left atrium and then ventricle and finally check the valves of the heart and fluid present in them.

Urinary Tract

In the urinary tract, both kidneys are cut down into two pieces, and examine them you can also see the surface of the bladder.

Respiratory System

The respiratory system should be cut from the trachea to bronchi to the lungs and bronchioles and made several cuts to the lungs to see the accurately to the internal section of the heart if you found the color of the lung is pink and spongy then the lungs are normal.


Cut the several edges of the liver to examine the abnormalities then open the gall bladder to see the fluid present in them and observe it.

Intestinal Tract

Now it is time to examine the intestinal tract spread the intestine and observe the intestine part one by one at the start of the duodenum then jejunum and finally the ileum if you need the feces for sampling to take them from the last part of the intestine the colon.


Examine the Rumen and stomach cut the stomach if you find any food material or mucosal fluid note them. [4]Diagnostic Necropsy and Selected Tissue and Sample Collection in Rats and Mice – PMC (

How to write a report after Examine Necropsy

After all the observations and examinations of all the organs write a note on which you and what disease cause the death of animals. Necropsy is incomplete if you don’t write the observations in written recorded form. A necropsy report should contain the following information.

 What is Importance of Necropsy?

  • The main and basic advantage of Necropsy is to conclude or observe the reason of death.
  • It is important for research purposes to research the infection or acute disease.
  • It is important for the understanding of anatomy, physiology, and pathological diseases.
  • It is important for suspicious death.[6]

Written by: Dr. Muhammad Mohsin Ahsan

Reviewed by:
Dr. Muhammad Tahir Ph.D. (
Post Doctorate

American Museum of Natural History, New York, USA