Begin with animal must be placed left lateral recumbency location, in cattle this allow the rumen down make it easier to visualize the abdominal organs.Inspect any signs of trauma and note any obvious abnormalities (lesions). Observe any discharge or blood that come out from nose , mouth, rectum or vulva again and external genitalia. Examine all the feet, joints and mammary glands.
Make first incision under the animal lower jaw, place the tip of your knife under the skin and make a smooth cut along the neck.Continue the skin incision along the body, between front limbs, and above the udder or external genitalia. Using knife, free the skin from the body wall on the right side of the animals up to the spine as far as possible. This is accomplished by cutting the connective tissue between the hide and the muscles of the animal. By cutting through the connective tissue you will able to reflect the limbs without cutting through any more of the hide. Prevent not make too many holes on the skin so that it will easier to close and remove the carcass after the necropsy is performed.
Reflect the right forelimb by cutting between the muscles of the shoulder an those body wall. Reflect the right forelimb by cutting between muscles of the shoulder and those of the body wall. Cut the connective tissue (clear to white colour between muscles) while pulling back on the limb. Don’t cut through the hide on the limbs. Then the right forelimb should be at a right angle to the rest of the body.
Lift the hindlimb up and cut through the muscle bellies toward the hip joint. Then you will see that it looks like a ball and socket. Cut the small ligament connecting to the ball to the socket. Cutting this ligament all ow the joint to come apart. Once cut, the hindlimb also should lay at a right angle to the body of the animal. If a cow, examine the mammary glands at this time. You will need to cut through all four quarters and evaluate the inner tissue. Make an incision in the abdomen just behind the ribs. Try not too deep in order to avoid penetrating the underlying forestomach and intestines. Reverse the knife in your hand so that the tip of the knife points toward yourself. Insert your hand the knife handle in the abdominal incision you previously create. Cut the abdominal wall along the rib and then continue the cut from the original point of entry towards the udder.
You should now have an abdominal flap that when folded down exposes the abdominal contents. Later this flap will serve to keep the organs contained within the carcass during removal of the animal. Examine the colour, position, size of all organs. Grab the greater omentum that covering the abdominal towards the hip joint and cut it away from the body wall of the abdominal organs. Once the abdominal organ is observed, examine the abdominal cavity for any adhesions, discoloration or masses.
Using knife, puncture the diaphragm while listening for air to rush into the chest cavity, normal the chest cavity is under negative pressure to keep the lungs inflate eventhough after death unless there has been trauma to the chest. Cut the entire right side of the diaphragm away from the rib cage. This allows for the first look into the chest cavity. Using your knife, cut the muscles covering the rib cage along the top of the rib cage where the ribs meet the spine.
By using rib cutters or an ax, cut the ribs along the incision you just created in the muscle. So 13 ribs that will be cut. Push down the ribs to fracture them at the junction between bone and cartilage. This will create a tray that may be used as a cutting platform during the necropsy. When both abdominal and chest cavities are exposed and can be examined for abnormalities. The samples can be taken for culture (bacteria , virus , fungus and etc) before the samples get contamination.
Now on the esophagus and trachea, begin cutting between the lower jawbone on either side of where the tongue lays. Reach in and pull out the tongue. Cut the soft tissue of the upper mouth while pulling on the tongue. Notice small bones which is Hyoid bones on either side of the tongue. They needed to be disarticulated or cut in order to completely take out the tongue with the esophagus and trachea. After cut them, you should be able to pull out the tongue, trachea and esophagus up to the point of the lung. You may have to cut away some tissue connecting these structures to the head and neck muscles.
At the point where trachea and esophagus meet(larynx) , cut the esophagus follow length to the lungs.
Observe any lesions, with a sharp knife or rib cutters, cut the larynx open and look for any lesions.
Cut the trachea lengthwise to the point of the bifurcation at lungs and examine any lesions.
Examine the thin sac surrounding the heart, cut open the sac and observe any adhesions and fluid. Observe any large amount of clear fluid, blood or pus in the heart sac.
The normal lung should be light pink color and spongy to the touch so observe any abnormalities appearance (lesions). Reflect the right lung by grabbing the tip of the lung closest to the diaphragm. Pull the lung toward the head, cutting any connective tissue. Observe the major vessels and airways of the lung.
Cut into the lung near the top of the heart, you should see some large openings close to each other once you have to cut into the lung. Use scissors and forceps to cut open the airways and vessels. Make lengthwise cuts in the lung to observe the deeper tissue of the lung. Palpate and examine the lung for any lesions or adhesions. Observe vessel and airways of the left lung by pulling on the trachea and esophagus. This cutting will alow the removal of the heart from lungs.
The heart is fully examined, this can be done with or without removing it from carcass. When it is in carcass, you are looking at the right side of the heart. Find the major vessel that enters the heart from the abdomen, this is vena cava. Cut with scissor, cut this vessel lengthwise contuining to the heart. Cut the tip of the heart and then cut back forwards the vessel that lea to lungs at the base of the heart.
Examine the inside of the heart including the valves.
Duodenum is attached to the duodenum. Cut the duodenum from intestine and make a lengthwise incision through the duodenum and abomasum. Examine inner surface of both organs. Abomasum has a smooth surface and liquid contents.The next compartment is omasum, firm and contain ‘leaves’ like a book. Then reticulum next compartment , smaller sac that has a honey comb appearance on the inside. Then the largest compartment is rumen, inner surface look like a shag carpet made from thousands of papillae. Examine any abnormalities, lymph node and lessions.
Liver large between organ between the rumen and diaphragm, note any lesions or abnormalities on the surface , then cut the liver for inner view. Gall bladder located within the liver, this sac like organ is green colour and typically about size of a grapefruit in an adult cow. Cut the ducts associated with the gall bladder and course through the liver. This is the site where liver fluke can be found.
Urinary bladder can be found within pelvis, take sample if bladder is full using clean needle and syringe. Cut open inner surface to examine. If a cow, examine the reproductive tract and note any pregnancy. If fetus present, examine the fetus and placenta take sample if necessary. The spleen can be found left side of the animal, under the rumen expose the spleen, make small incision to for sample. The spleen may be dark due to congestion with blood.
Start with kidney, lay the small intestine over the rumen, right kidney lies in a flat layer close to the spine next to the liver.Pull away the fat to expose the kidney, then wrap your hand around the kidney and pull it out towards the tail. Cut the kidney lengthwise to examine the inner tissue. Pull off the thin layer that cover the tissue to fully examine the outer surface of the kidney. The left kidney is found by reflecting the entire intestine over the spine of the animal. Cut where the intestine meet just above the rumen through the fat to expose the left kidney and examine it in the same manner as right kidney.
To remove the head, extend it back and cut the muscles of the neck directly behind the jar. Cut away all atttachments and transect the spinal cord. Hide the muscles above the vertebrae should now be cut free from body. Cut through the muscles until reach spinal canal. Once remove the head, observe any abnormalities.
Place all organs in the carcass and pull the hide over the body. Cut the small holes in the hide whithin 4 inches of the edge to decrease the amount of damage done to the hide. Tie the hide together with baling twine. Clean the area properly, wash hands , boots and coveralls before handling other animals.
Livor mortis- hypostatic congestion
Post mortem clotting of blood
Imbibition of hemoglobin
Imbibition of bile
Post mortem desquamation
Post mortem softening
Post mortem discoloration
Post mortem distention
Post mortem displacement
Post mortem rupture of organ and tissue