Poultry disease – Postmortem techniques with findings
Lalrinkima
Assistant Professor
Department of Veterinary Pathology
Institute of Veterinary Sciences and Animal Husbandry
SOA (Deemed to be University), Odisha
Abstract
Postmortem examination is the process of examining a dead body by carefully dissecting the carcass. Necropsy is the term used in veterinary practice to describe the post-mortem examination of animals and birds. Autopsy is the term used for postmortem examination in human beings. Identifying the cause of death is the objective for post-mortem examination. A postmortem examination must be performed by a veterinarian on animals and birds that may have died naturally, as a result of an illness or unnaturally.
Keywords: Post-mortem techniques, post-mortem findings, poultry diseases
Techniques of post-mortem examination in poultry
- The carcass should be thoroughly moistened with clean water before opening for post-mortem examination.
- The external examination of the bird is carried out by stretching the feathers to look for lesions, wounds and ecto-parasites on both the dorsal and ventral aspects of the skin.
- Place the bird on its back with its legs and wings extended. Cut the skin on both sides between the legs and abdomen, then break open the hip joints and dislocate the femur’s head from the acetabulum to abduct the legs.
- Cut the skin transversely between the vent and the keel, then remove the skin surrounding the legs and abdomen.
- Cut open the abdomen by incising the abdominal wall transversely between the keel and the vent and remove the sternum by cutting through the ribs and clipping the coracoid and clavicles with bone cutter.
- Examine the muscles of the thigh and sternum.
- Examine the joints of the limbs.
- Part the thigh muscles and examine the sciatic nerve with ventral side up.
- Remove the sternum and expose the internal organs to study them in situ.
- Remove the stomach and intestine in one piece after cutting through the oesophagus just anterior to the proventriculus and at cloca and examine the organs beneath. Examine the bursa.
- Remove the different organs separately like liver separately with gall bladder and then the spleen.
- Remove the kidneys and record the lesion.
- Incise the pericardial sac and observe for presence of any pericardial fluid.
- Remove the heart by cutting the large blood vessels arising from the heart.
- Cut through the dorsal connection and separate the lungs from the thoracic wall using blunt dissection.
- Cut the beak transversely close to its skin attachment exposes the nasal cavity. Examine any abnormalities in the infra-orbital sinus by making an incision through the orifice on either side with the pointed end of the scissors.
- Open the mouth and cut from one angle of the jaw with the blunt point scissors inside the esophagus through the pharynx down the esophagus and open the crop.
- Similarly, open the trachea along its whole length from the larynx and examine.
- Cut and reflect the skin covering the skull and upper mandible to examine the brain. To expose the brain, carefully remove the skull and remove it.
- Record the lesions in the prescribed proforma.
- After necropsy give a “Pathological diagnosis” (Tentative/confirmative) based on the lesions recorded.
- After identification of the etiological agent, give an etio-pathological diagnosis.
Common post-mortem findings with diseases wise
| Name of the disease | Etiology | Common gross lesion |
| Newcastle diseases/ Ranikhet disease | Avian paramyxovirus type-1 serotype | Pin point haemorrhage at the tip of the proventricular gland,
haemorrhages in the caecal tonsils |
| Infectious Bursal Disease/ Gumboro disease | Birnavirus | Haemorrhages in the breast and thigh muscles, haemorrhages at the junction between the proventriculus and gizzard, enlarged and haemorrhagic bursa |
| Infectious Bronchitis | Avian coronavirus | Caseous plug may be found in lower trachea or bronchi |
| Infectious Laryngotracheitis | Gallid alphaherpesvirus
type-1 |
Trachea is inflamed red and contains blood casts |
| Fowl pox | Avipox virus | Nodular lesion on non-feathered skin (Cutaneous form) |
| Chicken Infectious Anaemia | Gyrovirus | Haemorrhages on the wings, generalized lymphoid atrophy of bone marrow and thymus |
| Avian Influenza | Avian Influenza virus (Orthomyxovirus) | Marked bluish discoloration of the external organs. Severe congestion in internal organs with haemorrhages in almost all organs |
| Marek’s disease | Gallid herpesvirus type 2 | Nodular lesion in feather follicles |
| Egg drop syndrome (EDS) | Aviadenovirus | Thin and soft shelled eggs |
| Hydropericardium syndrome/ Leechi disease | Aviadenovirus | Watery straw coloured fluid in the pericardial sac
|
| Infectious Stunting Syndrome | Enterovirus, parvovirus,astrovirus, calcivirus, arenavirus, togavirus, reovirus and rotavirus | Broken wing feathers (Helicopter feathering) |
| Pullorum disease | Salmonella pullorum | Presence of unabsorbed yolk sac, irregular ova cystic misshapen discoloured pedunculated with prominent thickened stalks in adults |
| Fowl typhoid | Salmonella gallinarum | Copper bronze sheen (glistening brightness on the surface) in liver |
| Colibacillosis | E.coli | Fibrinous pericarditis and perihepatitis |
| Fowl cholera | Pasteurella multocida | Multiple pin-point necrotic foci in the liver |
| Avian tuberculosis | Mycobacterium avium | Granuloma (tubercle) formation in liver, intestine, spleen and bone-marrow |
| Spirochaetosis/ Tick fever | Borrelia anserina | Marked enlargement and mottling of spleen. Enlargement with small haemorrhages and pale foci in liver |
| Ulcerative enteritis | Clostridium colinum | Small, circular to lenticular mucosal ulcers in small intestine, caeca and upper large intestine |
| Necrotic enteritis | Clostridium perfingens type A,C | Necrotic patches in intestine |
| Gangrenous dermatitis | Clostridium septicum and Clostridium perfingens type A | Dark moist area of the skin lying under the wings, between the thighs and over the ribs and flanks of birds |
| Infectious coryza | Haemophillus paragallinarum | Oedema of the face, cyanosis of the comb and wattle |
| Chronic respiratory disease | Mycoplasma gallisepticum | Uncomplicated cases result in relatively mild sinusitis, tracheitis and airsacculitis |
| Bumblefoot | Staphylococcus aureus | Abscess in foot pad |
| Candidiasis | Candida albicans | Turkish towel like appearance in crop |
| Aspergillosis | Aspergillus fumigatus | White or grey multiple granulomatous nodule in lungs |
| Coccidiosis | Eimeria spp | Caecal coccidiosis – Caeca is enlarged and distended with clotted blood
Intestinal coccidiosis – Ballooning of the affected part of the intestine with blood |
| White comb disease | Trichophyton megnini | Depression around feather follicles giving rise to “Favus cups” |
| Aflatoxicosis | Aspergillus flavus (B1,B2,G1,G2) | Multifocal haemorrhage in liver with yellowish discoloration |
| Ochratoxicosis | Aspergillus ochraceous | Acute tubular necrosis & urate deposition on visceral organ (visceral gout) |
| Heat stress | High environmental temperature,overcrowding | Cooked meat appearance of breast muscle |
| Gout | Metabolic disturbance | Visceral gout: Urate deposition in visceral organs as chalky gritty material
Articular gout: Deposition of urate in joints |
| Histomoniasis | Histomonas meliagridis | Saucer-shaped lesion in liver |
| Ascaridiasis | Ascaridia galli | Elongated white worms in intestine |
| Gapeworms (Tracheal worm) | Syngamus trachea | Red worms can be found in trachea causing inflammation, ulceration and accumulation of mucus in the trachea |
References
- Vegad J L (2018). Poultry diseases: A guide for farmers & poultry professionals. 2nd edition. CBS Publishers & Distributors. India.
- Prasana Kumar Rath, Susen Kumar Panda, Renu Singh and Bidyut Prava Mishra. (2025). Veterinary Pathology at your finger tips. pp. 106-161.
- Model training course manual on post-mortem techniques of livestock and poultry and handling veterolegal cases. Prepared by Department of Veterinary Pathology, Madras Veterinary College, Chennai.
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