Field necropsy techniques in mammal and poultry

Kidsadagon Pringproa, DVM, MS, PhD

Department of Veterinary Biosciences and Veterinary Public HealthFaculty of Veterinary Medicine

Chiang Mai University2012

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What is a necropsy?

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• Systemic examination of animal carcass aimed to search for

lesions and study the processes involved in disease situation

• The important diagnostic tool to support other procedures in

the diagnosis of disease outbreak

• A good necropsy involves carefully observation of lesions,

labelling and storage

Objectives in necropsy

• To investigation the caused of ill or death animals by defining

possible etiology and pathogenesis

• To provide information and support other procedures of

disease diagnosis (collection of specific organs, etc....)

• To provide initial strategy in control and prevention of un-

infected herds

The better job you do with the field necropsy, the better the chance that wildlife disease specialist can

determine what killed animal.

Necropsy requirements

• at the discretion of attending veterinarian

• When a high death loss occuring

• When a significant unexplained death occuring

• When a strong chance of infectious disease in present

A necropsy must be performed;

The necropsy must be performed by or under the direct

supervision of a veterinarian experienced with species

being necropsied.

5http://vetmed.illinois.edu/envirovet/programdeveloped.html

Necropsy requirements

It is recommended but not required that all death elephants be necropsied.

Objectives for this session

• Get an idea how pathology involves in “one health” concept

• Use images to review step-by-step procedures for field

necropsy procedure

• Understand the collection of appropriate tissue specimens for

diagnostic investigation

Limitation of necropsy

• Time for necropsy

• Place for necropsy

• Animals died from suspected transmissible, zoonotic or

exotic diseases should be examined in a laboratory !!!

• Disposal of the carcass

• Basic equipments and protective clothing for necropsy

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Necropsy equipment

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Equipment for sample collection

10% formalin Microbiology collection tools

Carcass submission form

1. Signalment: species, breed, sex, age, weight, identify marks

2. History and clinical diagnoses

3. Clinical pathology

4. External appearances

State of nutrition

Mucous membrane, body orifices

General conformation, superficial lesions

Hair coat, parasite

History taking

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Very important in determining the potential zoonoticdiseases, organs should be collect and types of laboratory

test should be performed !!!

Necropsy techniques in large and small

animals

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Necropsy procedure

• Follow external examination (general appearance)

• Follow internal examination ( necropsy )

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General appearances

– Natural orifices

– Eyes

– Posture

– Limb and joint palpation

– Lymph nodes

– Skin surface

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External examination

Open the carcass

• dorsal recumbency• Reflect front and rear legs

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• Make a tab of skin beginning under

the mandibles

• Pull up on the tap and reflect skin

while cutting through the sternum

Open the carcass

Small animal

Dorsal recumbency and cut the sternum through the costochondral

junction

Large animal

Left lateral recumbency and cut the ribs by using a pincer

Open the thorax

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Examine the lesions and prepare for collecting samples

stomach

trachea

lung

liver

intestine

Open the carcass

Open the thorax

Remove the tongue, esophagus, trachea, lung and heart

heart

Examine the lung, check for pneumonia and collect samples

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In a large animal, intestinal and thoracic organs may have to be remove separately

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Remove the intestine by cutting of the large and small intestines

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Examination of the stomach

String out the small intestine by cutting the mesentery

Examination of the intestine

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• Randomly sectioning of the intestine

(5-10 cm.) to observe the intestinal

mucosa

• Jejunum, ileum, cecum and colon:

two 10 cm section fresh/chilled, four 1

cm section fixed

Sampling techniques of the intestines

Examine the liver

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Examine the pericardium Fibrinous pericarditis

Examine the myocardium and endocardium

Nasal swab and snout scoring

Open the joints to examine the synovial fluid

Necropsy technique in poultry

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http://partnersah.vet.cornell.edu/Avian-Necropsy-Examination-Introduction

Additional resources

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Before necropsy

Wet the feathers with soapy water to avoid masses of flying feathers

Be careful of nasal and mouth orifices

Physical and external examination

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Check for the mucus membrane, and nasal swab if desired

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Open the abdominal cavity

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Keel bone

Intestine

liver

Open the abdominal cavity

trachea

Open the thorax

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Open the trachea

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lung

Examination of the visceral organs

heart

Examination of the visceral organs

intestine Gizzard and proventriculus

proventriculus

gizzard

Examination of the bones and head

Bone and skull are opened

Necropsy report

Morphologic findings

Morphologic diagnoses

Tentative diagnoses

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Tissue preservation for histopathology

Fixative

1. Neutral buffered formalin 10% (1 liter)

• Formaldehyde (40%) 100 ml.

• Distilled water 900 ml.

• Sodium phosphate mono. 4 g.

• Sodium phosphate dibasic 6.5 g.

2. Bouins solution (for endocrine disease, eye)

3. Glutaraldehyde (for electron microscopy examination)

4. Alcohol (not a good fixative)

Fix 24-48 hrs. Room temp.

Tips for sample collection

Formalin fixation

Work TM. 2000. Avian necropsy ,manual for biologist in remote refuges.

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Summary

• Necropsy technique in small mammal

• Necropsy techniques in poultry

• Tip for sample collection from carcass

Acknowledgements

Faculty of Veterinary Medicine, Chiang Mai University

• Assist. Prof. Panuwat Yamsakul, DVM

• Kittikorn Boonsri, DVM, MS

• Jiraporn Sritan, DVM, MS

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