Postmortem examination of small animals

NECROPSY DIAGNOSIS OF CANINE AND FELINE DISEASES

  • Demands placed upon the clinicians diagnostic ability by the varied and often obscure diseases of small animals require the application of postmortem examination.

Necropsy procedure for canines

  • Note the general condition of the hair
  • Examine for external wounds
  • Examine the superficial lymphnodes for enlargement
  • Examine the prepuce and penis in male
  • Examine the umbilicus in neonates
  • Place the animal with its dorsum upon table
  • The head is extended and the neck is straightened
  • Make an incision from the point of symphysis of mandibles to the ischial arch
  • The mammary glands are examined at this time
  • Separate the skin from the underlying tissues
  • The legs are pulled to the sides
  • Cut the coxofemoral joints and separate the hind limbs
  • Make an incision from the xiphoid cartilage to the pubis
  • Make transverse incisions from the midline to the dorsal extent of the body cavity
  • The abdominal cavity is exposed by removing the flaps
  • Examine the diaphragm
  • To expose the thoracic cavity, cut the sternal cartilage or ribs
  • Examine all organs in situ without severing the attachments
  • Incise the pericardial sac and examine its contents
  • Record the quantity, colour and contents of any fluids in the body cavities

Examination of cardiovascular system

  • Examine the pericardial surface of heart
  • Incise the pericardium and examine for thickening and abnormal contents of pericardial sac
  • Examine the epicardial surface of heart
  • Cut open the heart on right side first and then left side
  • Examine the contents of heart chambers
  • Examine the myocardium, endocardium and valves
  • Examine the adventitia of greater vessels
  • Open the great vessels and examine the intimal surface

Examination of respiratory system

  • Examine the nostrils and nasal cavity for ulcers and abnormal discharges
  • Examine the nasal cavity for lesions
  • Examine the pharynx for lesions
  • Examine the thyroid and parathyroids for lesions
  • Examine the thymus if present
  • Open the larynx and trachea and examine the lumen and the mucosa
  • Examine the mediastinal lymph nodes and make incisions and examine the cut surface
  • Examine the lung by palpation for any areas of firmness, nodules or lumps
  • Make multiple incisions in lungs on both sides including all the lobes and examine the cut surface
  • Open the bronchi and other airway

Examination of digestive system and related organs

  • Examine oral cavity for ulcers and abnormal discharges
  • Examine the teeth, tonsils, pharynx and salivary glands
  • Remove the tongue from its base by cutting between the lower jawbones
  • Open the oesophagus and examine
  • Remove and examine the spleen by slicing at multiple sites
  • Remove the liver and open the gall bladder
  • Examine the liver by cutting it across in multiple sites
  • Examine and collect lymph nodes along the mesenteric attachment
  • Find where the oesophagus enters the stomach and cut across the esophagus while holding the cardia closed to keep any food inside the stomach
  • Cut across the rectum while holding it closed to prevent feces from escaping
  • Remove the stomach and intestine as a unit by cutting the mesentery and cutting across the rectum
  • Leave the pancreas attached to duodenum and the spleen attached to the stomach
  • Open the stomach and intestine at the end of postmortem examination to prevent contamination of other organs and the necropsy table
  • Note the contents of the stomach
  • Note the content of the intestines (amount of food, presence of abnormal materials)

Examination of urinary system and related organs

  • The adrenal glands should be removed before the kidneys are disturbed.
  • Incise the adrenal and examine the cortex and medulla
  • Remove the kidneys and then remove the capsule after incising the organ longitudinally
  • Examine the cortex, medulla and pelvis
  • Examine the ureters on both sides
  • Open the urinary bladder and examine the nature of contents
  • Open the urethra and examine the lumen and mucosa

Examination of reproductive system

  • Remove the reproductive tract (testis if male; uterus and ovaries if female) and make a cut across the gonads and into the uterine lumen and oviduct
  • Open and examine the vagina, cervix, uterus, oviduct
  • Incise the ovaries in females
  • Examine the testis and accessory sex glands

Examination of sense organs

  • Examine the eyes
  • Examine the ears and ear canal

Examination of nervous system

  • Separate the head from the neck at the junction of the vertebra
  • Remove the skin from the top of the head and the skull
  • Strip off the muscles to expose the skull
  • Break open the skull with the help of a chisel and hammer
  • Cut the meninges and expose the brain
  • Dissect the brain into two halves
  • Preserve one half in buffered formalin and split the other half into containers for virology and toxicology
  • If rabies is suspected, dissect the hippocampus major
  • Collect pieces of the hippocampus major in glycerin for biological/virological examination and 10% formal saline for histopathology
  • Cut the vertebrae and examine the spinal cord

Examination of musculoskeletal system

  • Examine the ske letal muscles
  • Examine the long bones, costal bones etc., for lesions
Last modified: Friday, 23 March 2012, 10:19 AM