Post mortem Examination of animals and sample collection.pptx

This presentation covers the insights of postmortem examination in different species of animals. It also covers the postmortem artefacts and sample collection important for deducing the cause of death in animals.

1. Veterinary Forensic Medicine: Post Mortem Examination Published by: Dr. Desh Deepak Assistant Professor, Veterinary Medicine COVAS, SVPUAT, Meerut

2. Synonyms: Autopsy/Necropsy/ Obduction / Autopsia cadavarum PM examination is thorough examination of corpse by surgical dissection to determine the cause, mode and manner of death or to evaluate any disease or injury for research or education purpose PM Examination Objectives of performing PM Examination PM examination is performed to ascertain Time since death Cause of death

3. Must be performed on the written order of executive magistrate or police officer Carefully read the police report before conducting PM examination Note the time and date of arrival of carcass Donot delay the PM unnecessarily PM should be done in day light No unauthorized person except the investigating police officer should be allowed to be present while conducting PM examination. Each time PM examination must be thorough and complete All the observed details must be noted carefully in the PM report on spot at time of PM A veterinarian should have fair knowledge of normal and pathological appearance of viscera. Anthrax suspected carcass must not be opened. PM notes and the report sent to the court must tally each other Notes: PM report should contain concise but complete opinion regarding cause of death and should be forwarded to investigation officer within two days. Rules for conducting of PM Examination

4. Scissors (blunt, pointed and mayo) and scalpels Knives (different size), cartilage and bone knives Rib shearer Chisel, hammer and saw Forceps (different sizes) Gloves, hand lens, bucket and tumbler Balance and measuring tape Wide mouth bottles, Chemicals viz preservative (common salt and alcohol) and fixative (10% formaline , 50% glycerine, liquid paraffin, mercuric chloride, chromate, osmic acid. Requirement for conducting of PM Examination

5. External examination Note the general condition of carcass Note species, breed, age and sex of carcass Examine body surface for injuries, burns and swellings Examine genitalia and other body orifices for any sort of discharge Examine visible mucous membranes and genitalia Examine all bones and joints carefully for fracture and dislocation respectively 2. Internal Examination Equine must be kept in right recumbency, bovines in left recumbency and swine, canine and feline on their back while performing PM examination. Procedures for conducting of PM Examination

6. Place equine carcass in right recumbency (right side down) Internal examination in equines Incise the skin of ventral midline from chin to anus (dorsolateral around udder & penis) Reflect the skin of neck thorax and abdomen as much as possible without incising it and cut muscles and attachments to severe forelimb and hindlimbs. Finish skinning of thorax and abdomen upto the spinous process Make a incision from midline of xiphoid cartilage to pubis and from pubis to lumbar region and pull the abdominal flap upward & forward. Cut the diaphragm dorsoventrally close to its attachments Remove the abdominal viscera (Great colon & cecum, Left kidney, left adrenal , small colon, small intestine, liver, right kidney, right adrenal and stomach Open thoracic cavity by cutting along the ventral end of ribs from thoracic inlet to last rib and severe oesophagus and trachea and other attachments and lifting heart and lungs by cutting other attachments Cut the pubic symphysis and saw shaft of ileum above coxofemoral joint to examine internal genital organs, rectum and urinary bladder

7. Place bovine carcass in left recumbency (left side down) Internal examination in bovines Severe the forelimbs and hindlimbs by cutting all muscles and attachment (disarticulation of right hind limb facilitates further examination) Make a incision from jaw to perineal region (dorsolateral around udder & penis) and reflect the skin of the right side as much as possible. Open the rumen, reticulum, omassum and abomasum in situ and remove the contents to examine Open thoracic cavity by cutting along the ventral end of ribs from thoracic inlet to last rib and severe oesophagus and trachea and other attachments and lifting heart and lungs by cutting other attachments Cut the pubic symphysis and saw shaft of ileum above coxofemoral joint to examine internal genital organs, rectum and urinary bladder Make incision along the periphery of abdominal wall and open the abdominal cavity

8. Place swine carcass with their dorsum upon table (Back side on table) Internal examination in swine Drop the forelimbs and hindlimbs by making adequate inscisions Remove a strip of ventral body from chin to pubic region exposing trachea, esophagus, thoracic and abdominal cavities Incise the ventral abdominal wall towards pubis to expose the abdominal organs. Remove spleen, omentum. Remove liver, stomach and intestine together followed by adrenals and kidneys followed with genital organs (severe uterus as far as possible and examine seminal vesicles and other accessory sex organs of boar Open thoracic cavity by cutting along the ventral end of ribs from thoracic inlet to last rib and severe oesophagus and trachea and other attachments and lifting heart and lungs by cutting other attachments Cut the costal cartilages at the sternum while keeping the anterior end of sternum raised with left hand

9. Place the carcass with their dorsum upon table (Back side on table) & extend the head to straightened the neck Internal examination in canine & feline E xamine the mammae of the she dog while making a incision from point of symphysis of mandible to ischial arch and separate the skin from underlying tissue. Pull the legs to sides and cut the coxofemoral joint to separate the hindlimbs Make a incision from the xiphoid cartilage to pubis and a transverse incision from midline to dorsal extent of body cavity. Remove the flap to expose the abdominal cavity. Cut ribs or sternal cartilage to expose the thoracic cavity Examine all organs in situ without severing the attachments. Lift the organ and incise it for closer examination and keep the organ back to position in the cavity. Sequential orders of organ examination is mouth cavity, pharynx and larynx followed by cervical trachea and esophagus followed by lungs and heart followed by abdominal viscera (liver, spleen, adrenal , kidney, pancreas, stomach duodenum and intestine Disarticulate the head at atlanto -occipital joint and strip off the skin and muscles. Make a transverse cut behind the posterior margins of orbit and lateral cut (35-40 o ) from dorsal aspect of cranium meeting anteriorly and posteriorly. Open the calvarium and severe the olfactory and optic nerves to lift the brain

10. Post-mortem artefacts are the changes introduced in dead animal after death. PM artefacts are important since they can lead to misinterpretation in Wrong cause of death Wrong manner of death Undue suspicion of criminal offence Miscarriage of justice Classification of PM artefacts Putrefaction Environmental artefacts (burning, corrosion and maceration) Third party artefacts (by animals and birds, deliberate mutilation and while emergency treatments) Miscellaneous artefacts viz dragging marks or rope marks Post-mortem Artefacts

11. Post-mortem artefacts are the changes introduced in dead animal after death. PM artefacts are important since they can lead to misinterpretation in Wrong cause of death Wrong manner of death Undue suspicion of criminal offence Miscarriage of justice Classification of PM artefacts Putrefaction Environmental artefacts (burning, corrosion and maceration) Third party artefacts (by animals and birds, deliberate mutilation and while emergency treatments) Miscellaneous artefacts viz dragging marks or rope marks Post-mortem Artefacts

12. Putrefaction : most common artifacts developed after death. Common putrefaction artefacts include distension of abdomen with protrusion of tongues, bulging of eye balls, swelling of eyelids, lips, nose, udder etc, serosanguinous discharge from natural openings, post mortem vomition of ruminal contents, pm urination and defecation. Environmental artefacts include PM burning, PM corrosion and PM maceration. PM burns: Unusual burn lesions caused by exposure of dead body to direct flame or high temp. Singing of hair, hardening, cracking and charring of skin, baked appearance of underlying tissue, lack of tissue reaxn in tissue surrounding burn tissue. PM corrosion: is usually evident on body surface touching the ground and is caused by exposure to corrosive liquids like acids, caustic soda, effluents etc. PM maceration: On prolonged exposure of dead body to water mud etc. Post-mortem Artefacts

13. 3. Third party artefacts includes artefacts caused by animals and birds, deliberate mutilation and by emergency treatments. Third party artefacts inflicted by animals are common since dead body of animals is least cared and ears, eyes, nose, mouth, anus, vulva and udder are the first organ to be attempted. Deliberate mutilation like cutting of ear, cutting of tail, damaging scar is performed as a criminal attempt to mask the identity of animal. Emergency attempts made just prior to death or after death may leave some unnatural marks like rumen puncture, hematoma around juglar vein etc. 4 . Miscellaneous artefacts viz dragging marks or rope marks produced while transporting heavy dead bodies of animals. Post-mortem Artefacts

14. Quantity of specimen to be sent for toxicology examination Submission of specimen for chemical analysis Tissue/Organ Quantity Blood 30-50 ml Urine All available Hair 5-10 g Fat 200 g Liver and content of stomach and intestine 500-1000 g Brain Whole Kidney One Specimen for Histopathological examination: 0.5-1.0 cm thick specimen in fixatives about ten times the volume of tissue (formaldehyde, alcohol, mercuric chloride, picric acid, osmic acid and chromates)

15. Submission of specimen for chemical analysis S.No Suspected Poisoning Sample to be submitted 1. Mercury Liver, Kidney, stomach and intestine contents 2. Arsenic (Acute) Liver, Kidneys and stomach content 3. Arsenic (Chronic) Hair, liver and urine 4. Lead (Acute) Kidney, liver and urine 5. Lead (Chronic) Hair , liver, kidney and urine 6. Cyanide & Phosphorus Stomach content, liver and oxalated blood 7. Nitrate and Nitrite Stomach content and whole blood 8. Copper Liver 9. Chlorinated insecticides Fat, liver and stomach contents 10. Organophosphate insectiscides Oxalated blood, whole blood and stomach contents 11. Phenol -cresols Liver, stomach contents and kidney 12. Strychinine Stomach content, urine, liver, kidney and brain 13. Rodenticides Stomach contents, liver and kidney

16. Submission of specimen for chemical analysis Containers for viscera sample : As free wide mouth glass bottles of 2 liter capacity with air tight stoppers Preservative : Ethyl alcohol or rectified spirit* and saturate salt solution(for alcohol and volatile substances). Whole tissue must be dipped into the liquid with excess salt remaining at the bottom of bottle. Additional 25 ml alcohol or 25 g salt should be sent Blood sample : Sodium fluoride (20 mg/ml blood) and sodium citrate (5mg) and mercuric chloride (0.1 mg)/ ml blood Container should be properly sealed to prevent any sort of tempering without removing seal impression and packed again in wooden box with adequate packaging material and impression seal on it. Authorized letter to the examiner in laboratory with details of species, identification marks and location of lesion, list of articles, necropsy report, inquest copy, impression of seals used in closing the bottles, description of seals and mode of transmission

17. Submission of specimen for chemical analysis Containers for viscera sample : As free wide mouth glass bottles of 2 liter capacity with air tight stoppers Preservative : Ethyl alcohol or rectified spirit* and saturate salt solution(for alcohol and volatile substances). Whole tissue must be dipped into the liquid with excess salt remaining at the bottom of bottle. Additional 25 ml alcohol or 25 g salt should be sent Blood sample : Sodium fluoride (20 mg/ml blood) and sodium citrate (5mg) and mercuric chloride (0.1 mg)/ ml blood Container should be properly sealed to prevent any sort of tempering without removing seal impression and packed again in wooden box with adequate packaging material and impression seal on it. Authorized letter to the examiner in laboratory with details of species, identification marks and location of lesion, list of articles, necropsy report, inquest copy, impression of seals used in closing the bottles, description of seals and mode of transmission

18. Cause of sudden death in animals Spontaneous internal hemorrhages viz cardiac tamponade in cattle. Ruptured aorta in equine, rupture of middle uterine artery at calving and CVS accidents Peracute toxaemia and snake bites: Ruptures stomach and colon in mares and abomasum in cow Neonates: Congenital defects and septicemia Trauma cause death due to internal hemorrhages and CNS damage GI conditions like intestinal accidents in equines and bloat in cattle Bacterial and viral diseases: Anthrax, BQ, HS, Enterotoxaemia and FMD in calves Deficiency diseases: Falling disease of cattle (copper), Hypomagnesemic tetany and VESD Lightening stroke, electrocution and drowning Anaphylaxis: Injection of biological materials and iron in piglets (low VES) Medicinal reactions : Rapid IV infusion of calcium, IV injection of procaine penicillin, allergen and ivermectin (horse) Poisons: Cyanide, nitrite, OP, lead and fluoroacetate

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