NECROPSY PROCEDURE FOR RUMINANTS

Remove the right thoracic wall by cutting the ribs along the sternum and the vertebrae with the bone cutters.

Examine the thoracic and pulmonary pleura (normally smooth, shining and transparent; the thoracic fluid normally a small amount of clear, serous fluid). Remove the omentum.

Look particularly for exudates, transudates, adhesions and displacement of organs.

Pericardial fluid, if present in excessive amounts and required for further examination, is collected at this stage.

Cut along the mandibles.

Remove the tongue from between the mandibles and cut through the soft palate and the cartilaginous junction of the hyoid bones.

Cut the esophagus and the trachea from the neck as far as the anterior aperture of the thorax.

Remove the thoracic organs by cutting along the vertebral column and the sternum, then along the diaphragm, through aorta, esophagus and vena cava.

Inspect the exposed left thoracic wall.

Cut the ileum near its junction with the cecum if it contains a large amount of fluid material, cut between two ligatures.

Carefully cut the small intestine from the mesentery starting with the ileum.

Keep separating the small intestine from the mesentery until near the liver the small intestine disappears under the large intestine at the duo-jejunal flexure.

Lift the convolutions of the large intestine over the back of the animal, to expose the ascending duodenum.

Keep cutting the duodenum from the mesentery as far as it’s caudal flexure, where it disappears again under the large intestine.

Replace the large intestine in its original position and continue the now descending duodenum from its mesentery.

Sever the small intestine from the abomasum.

Remove both kidneys from the surrounding fat by blunt dissection and cut vessels and ureters. If the ureters are distended, pathological changes can usually be displayed more clearly if they are not separated from the kidneys but either cut at their posterior ends or if possible, the whole urinary tract is left intact.

Remove both adrenals, which are to be found just anterior to the original position of the respective kidneys. Use forceps and take care not to squash the tissue.

Cut through the rectum in the pelvis and separate it from the mesentery.

Cut the whole convolutions of the large intestine from its attachments, taking as much of the pancreas as possible with the large intestine.

Remove the stomach from the abdominal cavity by pulling its exposed side ventrally and cutting the dorsal attachment. The spleen will then come to lie on top and is immediately removed to avoid possible contamination with the ingesta.

Cut the diaphragm from the left thoracic wall and remove it along with liver.

• Urogenital tract is examined in situ. Cut the muscles from both sides of the pelvic symphysis.
• Cut the bones on both sides of the pelvic symphysis.
• Open the pelvic cavity by removing the separated bone section.
• Remove the urogenital tract and the rectum from the pelvic cavity by incising around the anus and vulva.

Open the bronchi, palpate the entire lungs. Cut areas of abnormal appearance. Cutting of the ventral side of the lungs, across the bronchi, gently squeeze the tissue.

Examine the pericardium (smooth, shining and transparent).

Examine the epicardium(smooth, shining, and transparent).

Examine the heart for hypertrophy, disproportions, dilatation.

Inspect the myocardium and endocardium and the valves.

Examine the liver on surface and cut surface. Open the gall bladder.

Examine the diaphragm, by inspection of serosa.

Examine the kidneys, remove any fat which is attached to the surface. Cut the kidneys in half longitudinally. Note any adhesions and examine cut surface.

Straighten the large intestine.

Examine the mesenteric lymph nodes and the pancreas.

Open the small and large intestines examine its contents, mucous membrane and other layers.

Palpate the position of the atlanto-occipital joint from the ventral side while moving the nose of the animal in a dorso-ventral direction.

Cut through the muscles of the joint. Open the joint with a short, forceful, dorsal movement of the head, holding the neck of the animal with your other hand.

Remove the head by cutting the remainder of the soft tissues, including the skin.

Remove the skin and then the muscles from the head. Saw the dorsal bones of the sull transversely, just behind the eyes, and then make two further cuts, laterally, from the foramen magnum to the lateral ends of the first cut just below the horns.

Thank You!

NECROPSY PROCEDURES FOR RUMINANTS

Dissection and Examination

of the Head

Examination of

Removed Organs

Inspect the surface of the tongue.

Open the pharynx by cutting the soft palate in the median plane with scissors. Examine tonsils, pharynx, and the retropharyngeal lymph nodes.

Open the esophagus. Examine lumen, contents and wall. The normal mucous membrane is whitish and shows longitudinal folds.

Open the larynx. Examine the epiglottis and larynx, as well as lumen, content and the wall of the trachea.

Midline Incision

Place the animal on it’s left side, the abdomen towards the prosector.

Cut the skin along the ventral midline from the mandibular to the pelvic symphysis.

Cut the operatinal wounds, penis, mammary gland, and in young animals the umbilicus, leaving them with the lower part of the abdominal wall.

Removal of Organs

Skinning

Skin the upper half of the body, cutting the pectoral muscles between the front leg and the thorax.

Removal of Organs

Disarticulation of the Hip Joint

Inspect the Position of

all Organs

If the gall bladder is distended and the animal is icteric, the patency of the gall bladder should be tested by opening the duodenum and gently squeezing the gall bladder to see if the bile enters the duodenum.

Take samples for bacteriological examination and open the joints which appear suspicious.

Cut through the medial muscles of the right hind leg, disarticulate the hip joint, and turn the leg away from the body.

Opening of the Abdominal Cavity

Examination of the Skinned Animal

Opening of the Thoracic Cavity

Cut away the exposed side of the abdominal wall along the last rib, the linea alba, and the vertebral column.

Examine the content.

Examine the exposed structures. Note the appearance of the blood.

Cut lymph nodes transversely. Note the size of the lymph nodes.

Inspect the position of the diaphragm. Normally it is arched into the thoracic cavity. If not, abnormal air content (air, fluid) in the thoracic cavity should be suspected.

Puncture the diaphragm and watch it relax, as air rushes into the thoracic cavity.

Cut the diagphram from the thoracic wall and briefly inspect the thoracic cavity.

photo credit Nasa / Goddard Space Flight Center / Reto Stöckli