Performing a post mortem examination
Looking carefully at the body and insides of a chicken that has
died of unknown reasons may help discover those reasons. Very sick birds, with
no hope of recovery, should be killed, using locally approved methods, or by
dislocating their necks.
It will be helpful to examine the insides and outsides of as
many healthy chickens as you can when they are slaughtered. Note the position,
size, color and texture of all internal organs. Then, when you work on a sick
bird, you will be better prepared to spot abnormalities.
This manual will not attempt to give instructions on how to
diagnose most diseases - that is best done by special publications with color
illustrations - but there are some signs you should look for.
Killing a Chicken. Stretch neck and
bend back around thumb.
Examine a bird as soon after death as possible, before body
conditions have changed. As you work, take good notes. They will help
veterinarians or lab technicians, if they are available, to identify the
problem. Ideally, you would take or send a few sick but still living chickens to
the vet or lab for diagnosis, but this often is impractical.
In a post mortem, first examine the outside of the bird. Look
for lice or mites, particularly around the vent, that may have contributed to
the death. Discolored head parts, such as the comb and wattles, are indications
of a number of diseases. Straighten the neck, pull the tongue and examine the
throat and windpipe for cheesy nodules (lumps), signs of pox. Check the nostrils
for a putrid smell. If the legs are rough, scaly and swollen, it may indicate
mites. Look for swollen leg and wing joints and excessive abdominal fat. Also
look for blackened spots which can be caused by scorpion stings.
Open the bird carefully. With a knife or shears, cut through the
side of the mouth and esophagus. Look for the lesions (injured areas) of pox,
fungus, excess blood or mucus, and other abnormalities and foreign matter and
nodules. Slit the larynx and trachea, looking for excess mucus, inflammation,
blood and cheesy matter.
To look inside the bird, first slit the skin over the hip joints
and dislocate them so that the body lies flat. Puncture and cut the skin from
just below the point of the breastbone to the head. Pull the skin flaps aside to
bare the breast. With heavy shears, cut through the heavy bones and ribs on both
sides of the keel (center ridge of breastbone), and remove the keel and breast
muscle. Do this with care or you will damage the internal organs. Check for
fluid in body cavity. In females check body cavity for broken egg yolks (a black
fluid if broken yolk has been in body cavity for a while).
Slit the crop, remove food (noting if it smells sour), and
examine lining for worms, fungus and other problems. Examine the liver, noting
its color (normal is dark brown), and looking for lesions or nodules (soft ones
may indicate leukosis). Check the heart for lesions, hemorrhages on the fat, and
cheesy matter or fluid inside. Examine the spleen and bronchial tubes for
lesions and nodules. Note the color and texture of the lungs (normal, bright red
and spongy, will float in water). Look for fluid (pneumonia), tumors, nodules,
and congestion (dark red, will sink in water).
Remove the intestines and look for tumors, nodules or
hemorrhages. Slit the intestines to check for worms and other problems.
Thickened intestinal walls may indicate microscopic worms or coccidiosis. Also
look for blood, inflammation and excess mucus. If you find blood in the ceca,
look for cheesy matter, scarred lining and cecal worms.
Open the proventriculus (true stomach, located at the joining of
the esophagus and gizzard), checking for hemorrhages, worms, or inflammation.
Slit the gizzard, looking for erosion. Gizzard erosion most often is caused by a
nutritional deficiency and is indicated when ulcers and/or peeling of the
gizzard lining is seen. Check the kidneys for urates (white material) in
internal passages. Examine the brachial nerves - if swollen, may indicate
leukosis. Note gall bladder size and color (normally green). In layers, check
the ovary and oviduct for excess fat and ruptures (breaks) that lead egg yolk
into other body