Field necropsy techniques in mammal and poultry Kidsadagon Pringproa, DVM, MS, PhD Department of Veterinary Biosciences and Veterinary Public Health Faculty of Veterinary Medicine Chiang Mai University 2012 1
What is a necropsy? 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 2
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 uninfected 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 A necropsy must be performed; 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 The necropsy must be performed by or under the direct supervision of a veterinarian experienced with species being necropsied.
Necropsy requirements It is recommended but not required that all death elephants be necropsied. http://vetmed.illinois.edu/envirovet/programdeveloped.html 5
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 7
Necropsy equipment 8
Equipment for sample collection 10% formalin Microbiology collection tools 9
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 Very important in determining the potential zoonotic diseases, organs should be collect and types of laboratory test should be performed!!! 11
Necropsy techniques in large and small animals 12
Necropsy procedure Follow external examination (general appearance) Follow internal examination ( necropsy ) 13
General appearances Natural orifices Eyes Posture Limb and joint palpation Lymph nodes Skin surface 14
External examination 15
dorsal recumbency Reflect front and rear legs Open the carcass
Open the carcass Make a tab of skin beginning under the mandibles Pull up on the tap and reflect skin while cutting through the sternum 17
Open the thorax 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 carcass liver stomach trachea intestine lung Examine the lesions and prepare for collecting samples 19
Open the thorax heart Remove the tongue, esophagus, trachea, lung and 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 23
Remove the intestine by cutting of the large and small intestines 24
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Examination of the stomach 28
Examination of the intestine String out the small intestine by cutting the mesentery 29
Sampling techniques of the intestines 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
Examine the liver
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Examine the pericardium Fibrinous pericarditis 34
Examine the myocardium and endocardium
Nasal swab and snout scoring
Open the joints to examine the synovial fluid
Necropsy technique in poultry 38
Additional resources http://partnersah.vet.cornell.edu/avian-necropsy- Examination-Introduction 39
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 Check for the mucus membrane, and nasal swab if desired 41
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Open the abdominal cavity 43
Open the abdominal cavity trachea Keel bone liver Intestine 44
Open the thorax 45
Open the trachea 46
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Examination of the visceral organs lung heart 48
Examination of the visceral organs proventriculus intestine gizzard Gizzard and proventriculus
Bone and skull are opened Examination of the bones and head
Necropsy report Morphologic findings Morphologic diagnoses Tentative diagnoses 51
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.
Summary Necropsy technique in small mammal Necropsy techniques in poultry Tip for sample collection from carcass 54
Acknowledgements Faculty of Veterinary Medicine, Chiang Mai University Assist. Prof. Panuwat Yamsakul, DVM Kittikorn Boonsri, DVM, MS Jiraporn Sritan, DVM, MS 55