When chickens are sick, the owner is immediately interested in finding out what has brought on the condition, and what should be done to cure or prevent it. A diagnosis or study of the external symptoms is first necessary. Afterward, a postmortem examination may be advisable. The farmer seldom has facilities or the training to do this and, when necessary, should turn such work over to a trained veterinarian or state laboratory.
How to make an external examination
When examining the external symptoms of sick birds, the following points should be taken into consideration:
- Appearance of the head. No part of the chicken’s body reflects its condition more promptly than the head. The size, color and feel of the comb and wattles; the brightness and color together with the prominence or sunken condition of the eyes; the size, shape and fleshing of the skull, and the position and condition of the feathers, help in diagnosing a diseased condition. Every poultry-keeper should know what a healthy bird’s head looks like, as compared with one that is not.
- Condition of flesh. Loss of flesh or condition is an important symptom.
- Condition of the plumage. Sick birds usually show a ruffled or mussy condition of the feathers. This may not be true of all diseases, but it is for most of them. It is always well to look for lice and other external parasites with this condition, if nothing more.
- Condition of the skin. The scales on the legs and feet and the body skin should be examined for any unusual condition.
- Deformities and injuries. The bird should be examined for an abnormal condition of the body or possible infection such as sores, canker, frostbite, injuries and the like.
Note the condition of the bowels. Many poultry diseases affect the bowels in one way or another, but most often by causing diarrhea.
How to make a postmortem examination
- Find a table, barrel or box of convenient height and locate it either out-of-doors or in a room where there is good light. Secure a small sharp scalpel or pocket-knife with a slender blade. Spread a newspaper on the table, then place the dead bird on it with the back down and the feet toward the operator. Grip the end of the keel-bone with the left hand, and, with the right, cut the skin and flesh on the body from the thigh on the right side around just above the vent to the thigh on the left side. Peel back the skin over the breast-bone to the crop. Break down the leg-bones at the hips so that they will lay flat on the table and will be out of the way. Hold the keel-bone firmly with the left hand and then break the back downward with the right hand.
- This will expose all the internal organs. Carefully tear or cut the tissues which hold the intestines in position and spread them out near the body. If necessary, the head can be split lengthwise toy placing a butcher-knife on it and striking the knife once or twice with a hammer.
- Examine the vital organs systematically. Begin with the liver, spleen and gall-bladder because they are dose together. When perfectly healthy, the liver will be a rich chocolate-brown color free from White or grayish spots or lumps, and firm to the touch. The spleen is similar in color and texture to the liver, but it’s much smaller. The gall-duct, dark green in color, is attached to the liver and is about % inch in diameter.
- Next, examine the lungs and heart located near the front of the body. Healthy lungs have a light red color.
- After looking at the crop, proventriculus or stomach and gizzard, the ovaries, oviduct and kidneys are inspected. The kidneys are imbedded in the back of the bird toward the rear of the carcass and are similar in color and texture to the liver.
- Lastly, the intestine and caeca (two blind pouches) are opened full length for evidence of worms or inflammation.
The normal color of the intestines is light gray. They should be free from wrinkles or nodules. To get the most out of an autopsy, the operator should be familiar with the appearance and condition of the organs in a healthy bird.
A postmortem examination takes only a few minutes and is a valuable supplement to the external examination in arriving at a correct diagnosis of disease.