CATDOLL : CATDOLL: What are the typical symptoms and pathological changes in chicken aflatoxin poisoning?

1. What are the typical symptoms and pathological changes in chicken aflatoxin poisoning?

The main purpose of pathological autopsy is to observe and analyze the various tissues and organs of sick chickens, determine the location, nature and extent of pathological changes, and provide an objective basis for determining the nature of the disease.

Therefore, the autopsy must be carried out scientifically in a certain order to avoid missing the diagnosis or even damaging some organs due to improper operation, which may lead to wrong judgment. The autopsy must be carried out on sick chickens that are dying or have just died, because the pathological changes of sick chickens at this time more typically reflect the disease and have clinical diagnostic significance.

The order of pathological dissection is from the outside to the inside, first from the body surface to the body cavity, and then observe each organ in the body cavity one by one, from the surface to the inside. Mainly observe whether various tissues have bleeding, stasis, congestion, edema, necrosis, ulcers, tissue hyperplasia or tumors, etc.

(1) Body surface tissue. First, check the surface tissue of the chicken's body, pay attention to the body condition of the sick chicken, the state of the head, face and natural pores, and whether there are tumors or external parasites on the body surface. Then use gauze soaked in disinfectant solution to fully wet the feathers so that the feathers and attached dust will not fly everywhere, so as to facilitate the autopsy.

(2) Dissect the body cavity and examine the subcutaneous tissue. First, place the body on its back on an enamel tray or gauze pad, and use a scalpel or a sharp blade to cut the loose skin between the abdominal wall and both thighs vertically, severing the fascia at the connection, and at the same time flattening both thigh bones to separate them from the abdominal wall, so that the body lies flat on its back for easy dissection.

Next, make a transverse incision in the skin of the abdominal wall at the end of the keel, connecting the incisions on both sides of the thighs to fully expose the subcutaneous tissue and muscles of the entire chest, abdomen and neck. Carefully check the development, color and bleeding of the pectoral muscles, subcutaneous edema, and blood congestion or bleeding in the blood vessels.

Finally, open the body cavity, that is, further cut the abdominal wall of the posterior abdomen between the keel and the anus horizontally, extending to both sides of the abdomen; then cut the ribs and pectoral muscles forward along the rib joints from both sides of the abdominal wall, cut the coracoid bone and clavicle, and turn the entire chest wall toward the head, clearly revealing the entire chest, abdomen and abdominal organs.

(3) Check the internal tissues and organs. First, do not touch the organs in the body cavity and check whether they have lesions in their natural state. Then use sterile instruments to collect samples that need to be diagnosed in the laboratory. Intestinal tract samples should be collected last.

Digestive system examination: Cut off the end of the esophagus and take out the entire gastrointestinal tract: glandular stomach, gizzard, pancreas, small intestine and large intestine (including cecum). Use scissors to cut the glandular stomach and gizzard longitudinally, observe the mucosa and epithelial tissue, and pay attention to the presence of parasites. Chickens with Newcastle disease may often have bleeding glandular stomach papillae, and some may even form ulcers. Secondly, cut off the duodenum and carefully examine the outside of the duodenum and cecum to see if there is congestion; then cut the intestinal tube open and examine the intestinal contents and mucosa. For example, the characteristic lesions of Newcastle disease in chickens are acute catarrhal or hemorrhagic inflammation of the small intestinal mucosa, with scattered hemorrhagic ulcers covered with pseudomembranes on the surface; chicken intestinal coccidiosis contains a large number of small grayish-white spots in the small intestinal mucosa, without ulcers; chicken tuberculosis, leukemia, Marek's disease, malignant tumors and severe tapeworm diseases produce tumor nodules of varying sizes on the intestinal wall; chicken cecal coccidiosis or histomoniasis is characterized by an enlarged cecum and blood or hard emboli in the intestinal cavity.

Liver and spleen examination: First, visual examination. Check the size, hardness, color, bleeding and other lesions of the liver and spleen. In chickens with Marek's disease or lymphatic leukemia, the liver and spleen are enlarged, the color becomes lighter, and there are grayish white spots or tumor nodules of varying sizes on the surface; acute cholera in chickens may cause grayish white necrotic spots of varying numbers on the surface of the liver. The manifestation of chicken tuberculosis is the appearance of a large number of grayish white or light yellow nodules on the surface of the liver and spleen with a cheese-like cross section.

Examination of kidneys, ovaries and testicles: The kidneys of healthy chickens are lobed and closely attached to the bone structure of the abdominal wall. The ovaries are often located on the left side, while the ovaries on the other side are underdeveloped. The volume and color of the kidneys, the shape, size and color of the eggs, and the integrity of the oviduct wall are mainly observed in situ. Chickens with Marek's disease or lymphatic leukemia often have significantly enlarged kidneys, ovaries or testicles, which are grayish white. When chickens suffer from renal infectious bronchitis or visceral gout, there are white urate deposits on the surface of the kidneys, and the ureters are dilated and filled with white urate; in chronic pullorum and fowl typhoid, it is common to see that the ovaries are irregular in shape and change in color.

Examination of the heart and lungs: mainly check the inner and outer membranes of the heart, the color of the myocardium, the contents of the pericardium and the presence of adhesions; the color and texture of the lungs, the state of the air sacs, etc. When chickens suffer from acute septicemic infectious diseases, there are usually bleeding spots on the inner and outer membranes of the heart; in chickens with pullorum and typhoid fever, small gray-white necrotic spots can be seen on the epicardium; exudates containing cellulose clots accumulate in the pericardium of chickens with cholera, Escherichia coli and salmonellosis; small gray-white or yellow-white nodules form on the lungs and air sac membranes of chickens with aspergillosis; and gray-white needle-sized nodules appear on the lung surface of chickens with pullorum.

Examination of the bursa of Fabricius: Cut off the connection between the bursa and the cloaca to allow it to fall off, examine its surface and size, and cut it open to examine its contents.

Inspection of the crop, esophagus and trachea: Turn the head of the carcass upward, cut open the upper commissure of the mouth, oral cavity and pharynx, and then the esophagus and crop. First, check the entire upper esophagus, paying attention to the mucosa and contents. When the chicken crop is constipated, the crop is swollen and filled with sour and smelly food or hard plant roots. Next, cut open the entire trachea and both sides of the bronchi from the larynx to check the upper respiratory tract. In infectious laryngotracheitis, the trachea shows hemorrhagic inflammation, containing cheesy exudate or hemorrhagic mucus. In infectious bronchitis, the trachea contains mucous exudate and there is cheesy substance blocking the bronchi.

Nervous system examination: Turn the body back up, remove the skin and feathers on the back, and check the brachial plexus between the shoulder blade and the spine. Return to the original supine position, separate the thigh muscles, and check the sciatic nerve. The symptoms of neurological Marek's disease are that the volume of nerve fibers increases significantly, and the color becomes gray or yellow-white and translucent. If necessary, check the central nervous system, remove the skin on the head, cut the skull with bone scissors or large scissors, carefully separate the entire brain and cerebellum, and observe the changes in the size, shape, color and texture of the cerebellum and cerebellum.

2. What are the typical symptoms and pathological changes of fowl cholera?

1) Acute type: caused by highly virulent strains, characterized by fever, decreased appetite, increased oral and nasal secretions causing difficulty breathing, shaking the head to try to expel mucus from the throat, diarrhea, and yellow-green loose stools.

The egg production of laying hens decreases, and they usually die 1-3 days after the onset of the disease.

During the autopsy, bleeding spots were seen on the coronal fat, the liver and spleen were enlarged, brittle, and covered with a large number of round, gray-white necrotic spots as big as a needle tip. There was severe intestinal bleeding, the intestinal contents were gelatinous, the intestinal lymph nodes were annularly swollen and bleeding, some had bleeding in the subcutaneous fat of the abdomen, and the follicles of laying hens were bleeding and ruptured.

(2) Chronic type: common in the late stage of an epidemic, it may also be transformed from an acute type. Sick chickens show symptoms of emaciation, diarrhea, rhinitis, arthritis, and swollen wattles.

The course of the disease is long and can last for several weeks, causing a decrease in egg production in laying hens.

3. What are the typical symptoms and pathological examination of infectious bronchitis in chickens?

The symptoms and lesions of infectious bronchitis are relatively complex and can be divided into the following types.

(1) The respiratory tract disease type mainly manifests as depression, gathering around heat sources, breathing with open mouths, coughing, sneezing, and rales when inhaling. Sick chickens eat less, have diarrhea, and have elevated body temperatures. Infected chicks have runny noses and may die in severe cases. When large and medium-sized chicks are infected, the "gurgling" sound is more obvious than that of young chicks because of the accumulation of mucus in the trachea.

The larynx and trachea of ​​sick chickens have watery or sticky yellow-white secretions, and the mucosa is congested, edematous, and thickened. The air sacs are turbid and thickened, with yellow-white cheesy exudates.

(2) Egg-laying abnormality infectious bronchitis virus can attack the ovaries and fallopian tubes, and the symptoms vary depending on the age of the infected chickens.

After young and middle-aged chicks are infected, the eggs they lay in the future will contain more deformed eggs, lime-like eggshells, watery egg whites, or low-quality eggs with separated yolks. Some chickens may also suffer permanent damage to their reproductive organs and lose the ability to lay eggs.

When chickens are infected with the virus before or after the start of laying, the start of laying will be delayed, abnormal eggs (soft-shelled eggs, thin-shelled eggs, rough eggshells), irregular eggs, uneven sizes, and abnormal egg contents (watery or turbid egg white, egg white and yolk separation, etc.). When laying hens are sick, in addition to mild respiratory symptoms, the egg production rate can be reduced from 70% to 30%.

The pathological changes of this type of disease are manifested as incomplete development of the fallopian tube, short and rough fallopian tube, narrow and occluded lumen, and local cyst formation. The yolk coagulates or cysts, some follicles become congested and hemorrhaged, or the follicles soften and rupture, the yolk flows into the abdominal cavity, the peritoneum becomes turbid and yellow, there is coagulated yolk in the abdominal cavity, and the ascites is yellow and turbid. Sometimes, because the fallopian tube hinders the formation of eggs, the discharged eggs fall into the abdominal cavity, causing yolk peritonitis.

(3) The nephrotic syndrome is more common in chickens aged 3 to 10 weeks. Mild respiratory symptoms appear at the beginning of the disease, which last for 1 to 4 days. At this time, the symptoms are mild and difficult to detect. After that, the number of chickens suddenly increases. The sick chickens huddle together, lose their appetite, become thirsty, excrete watery white feces, lose weight, turn purple on the face, darken the comb, and hunch their backs. Deaths begin 6 to 7 days after infection, reach a peak of mortality 10 to 12 days later, and stop after about 20 days.

48 hours after laying hens show mild respiratory symptoms, egg production begins to decline, which can drop by 30% to 50%. The eggshell becomes rough and the egg shape becomes round. When incubating eggs with these eggs, the number of dead embryos increases by 10% to 30%. After the sick chickens recover, the egg production will not return to the original level.

Autopsy of dead chickens showed enlarged kidneys, which became lighter in color to yellow, and the renal tubules and ureters were dilated due to urate deposition, giving the kidneys a red and white "speckled" appearance.

(4) Urolithiasis is a type of chronic nephritis caused by infectious bronchitis virus. Sick chickens appear thin, with pale combs and white feces on the feathers around the anus.

The autopsy showed kidney atrophy, ureteral dilation, and a large number of 1 to 5 mm sand-like urinary stones in the lumen.

(5) Glandular gastric lesion type A new type of disease discovered in recent years occurs in chickens aged 20 to 90 days. At the beginning of the disease, the chickens grow slowly, eat less and drink less, have diarrhea, and have respiratory symptoms. In the middle and late stages of the disease, the chickens droop their wings, close their eyes, and have ruffled feathers. Some chickens breathe with their mouths open and cough. The chickens become emaciated, and the weight of the chickens varies greatly. Finally, the chickens die of severe exhaustion.

Autopsy showed that the glandular stomach was swollen and rounded, the glandular stomach wall was thickened, the glandular stomach mucosa was bleeding and ulcerated, and some chickens had swollen and bleeding glandular stomach papillae or the papillae disappeared, necrotized, and sunken glandular stomach papillae, with milky white viscous fluid flowing out, and the intestines were swollen and bleeding to varying degrees, with obvious swelling of the duodenum. About 30% of sick chickens were accompanied by kidney enlargement or urate deposition.

In addition, British scholars have isolated an infectious bronchitis myopathy virus strain from broiler chickens that can cause purple muscles, tremors, and difficulty breathing, leading to rapid death. Autopsy revealed severe tracheal inflammation and bilateral muscle hemorrhage.

4. What are the steps for pig autopsy?

Pig autopsy is a common method of disease diagnosis and prevention, which is widely used in pig farms and veterinary clinics. Its steps include the following aspects:

1. Preparation of the pig: First, select a healthy mature pig for autopsy, fix the pig on the operating table, clean the pig's abdomen, and perform local anesthesia.

2. Determine the opening position: Depending on the location of the opening, it is usually made from the midline of the abdomen or the nipple space.

3. Opening the chest: After completing the above steps, open the chest. Use surgical incision suture clips to clamp the edges of the surgical incision and remove the tense muscles.

4. Observe the internal organs: After opening the body, take out the internal organs one by one for observation, such as liver, spleen, lung, kidney, stomach, etc.

5. Collecting samples: While observing the organs, take samples of any organs or tissues found to be abnormal.

6. Clean the viscera: To facilitate observation and sampling, the viscera can be cleaned and placed on the workbench.

7. Examination of specimens: Conduct specific examinations on the collected tissue specimens, such as chemical analysis, cytological analysis, and virological analysis.

Through pig autopsy technology, veterinarians can detect diseases and abnormalities in a timely manner, diagnose and treat them, thereby ensuring the health and output of pigs.

5. How to cut shrimp?

How to peel mantis shrimp

1. Mantis shrimp is a kind of elephant shrimp. You need to remove its outer shell when eating it. When peeling the mantis shrimp, you can twist off the two outermost small feet of its tail, then pinch its tail, fold it upwards, and then twist it off.

2. Use a clean chopstick to insert the chopstick from the tail of the mantis shrimp along the shrimp shell to near its head. Then hold the chopstick with one hand and use the other hand to push the shrimp shell outward. This will completely separate the shrimp shell from the shrimp meat inside. After getting the shrimp meat, you can eat it directly.

How to peel crayfish

1. When eating crayfish, you can first remove the crayfish's claws, then twist the joints along the end, eat the shrimp meat in the claws, then hold the crayfish's body with one hand and the shrimp head with one hand, and gently twist it to remove the shrimp head.

2. Use your hands to twist off the shrimp tail, then use your hands to peel open the belly of the crayfish, take out the shrimp meat inside and enjoy the delicious taste directly.

How to peel prawns

There are certain methods and techniques for peeling the common prawns. When peeling the shell, you should first peel from the third section of the prawn's back, remove the shrimp head after peeling, and then peel from the third section to the tail. Finally, hold the tail of the shrimp and pull the exposed shrimp meat hard to completely separate the shrimp shell and get the intact shrimp meat inside. At this time, remove the shrimp thread and clean it, then you can directly eat the fresh and tender shrimp meat.

6. How to cut a pomegranate?

Use a knife to make a horizontal cut at the top of the pomegranate. Be careful not to damage the flesh when cutting. Then remove the shell and core on the top. Use a knife to slowly cut the peel in a circular shape at the bottom. Don't cut too deep. Just cut the peel together with the flesh. Then use a knife to cut the pomegranate peel vertically along the white veins of the fruit. Use the tip of the knife to gently cut the white veins inside. After cutting the white veins, it will bloom slightly along the cut shape. When eating, it can be easily broken apart with just a light piecing.

7. How to cut open mullet?

How to cut open mullet

1. First, clean the fish to facilitate handling. Mainly remove the mud or dust on the fish, and then rinse it repeatedly with clean water.

2. Next, put the cleaned fish on the chopping board, hold the fish body with your left hand, and use a rolling pin or the back of a knife to hit the top of the fish head a few times with your right hand to make the fish unconscious and reduce its struggle. This is mainly to make it easier to handle and prevent it from jumping around, so that it is easier to dissect.

3. Once again, place the stunned fish in the sink and scrape off the scales (the scales on the belly are relatively small, so be careful to scrape them clean). Generally, you can use a blade or fingernails to peel off the scales layer by layer, and then rinse it with clean water.

4. Then, continue to hold down the fish that has been almost processed, lift the gill cover with your left hand, and dig out the gills. Remember to dig them out cleanly without leaving a trace of red gills, and then rinse them with water.

5. Then, continue to hold the fish on the chopping board with your left hand, and use a knife or scissors in your right hand to scrape open the belly of the fish, starting from the cloaca and going all the way to under the gill cover. It is best to cut in a straight line until the whole fish can be broken apart.

8. How to cut a pomelo?

The fastest way to plan a grapefruit:

First, cut off the top and bottom of the grapefruit, and then cut it in half from the middle. Cut the grapefruit in half, and the grapefruit is tightly connected. Break each segment apart, and then you can quickly peel the grapefruit flesh. In this way, the grapefruit flesh and grapefruit skin are separated, and a grapefruit can be peeled in a few minutes. Except for the cut, the grapefruit is generally intact and not squeezed, and the moisture of the grapefruit is not lost. It is a very fast way to peel grapefruit.

9. What is the method of dissection?

The commonly used cutting methods are as follows.

1. Full section view. The section plane is usually selected along the axis of the part. This section method is for relatively simple parts.

2. Partial sectional view: This sectional view mainly cuts a part of the part, and is generally used for more complex parts, such as reducer housing or frame, etc.;

3. Half-section view: This section view is mainly used for rotating parts such as circular gears or pulleys. Its section view is along the rotation axis of the part to the rotation generatrix (that is, half of the part);

4. Stepped sectional view is mainly used for assembly drawings and parts with many processing holes or modeling surfaces, such as multi-stage spur gear reducers where the gear axes are not in the same plane. Generally, the sectional view is taken along the gear meshing surface;

5. Rotated section view is used to represent different planes of a part on the same view frame, but the turning line of the section surface is generally the rotation axis or symmetry line of the part.

10. What is the order and steps of autopsy?

Generally, autopsy is performed on the surface of the body first and then on the inside of the body. The usual order of autopsy is as follows:

① External examination of the corpse: observe the condition of the coat, skin, conjunctiva, and natural pores, and check the nutritional status of the animal and the presence of external parasites.

② Internal examination of the corpse: ⑴ Skinning and subcutaneous examination. ⑵ Opening the abdominal cavity and visual examination of abdominal organs. ⑶ Opening the chest cavity and visual examination of chest organs. ⑷ Removal of abdominal organs. ⑸ Removal of chest organs. ⑹ Removal of oral and cervical organs. ⑺ Examination of cervical, thoracic and abdominal organs. ⑻ Removal and examination of pelvic organs. ⑼ Opening the cranial cavity, removal and examination of the brain. ⑽ Opening and examination of the nasal cavity. ⑾ Opening the spinal canal, removal and examination of the spinal cord. ⑿ Examination of muscles and joints. ⒀ Examination of bones and bone marrow.