What is the disease of sheep digestive tract nematode? What are the main manifestations of gastroint

Sheep with suspicious symptoms are usually examined for fecal eggs. Rectal stool or fresh stool can be taken before death, and the most common methods are saturated saline floatation and direct smear microscopic examination of eggs, and egg counting can be done if necessary. Specific method of saturated brine flotation method:

Take 5 10 grams of suspicious feces, add 10 20 times saturated saline and mix well, filter through a millimeter pore size (60 mesh) with a mesh, and let the filtrate stand for 1 hour, then the eggs have fully floated, and use a wire loop with a diameter of 5 10 mm to contact the liquid surface parallel to the liquid surface to dip the surface liquid film, shake the liquid film on the slide, and cover it with a coverslip for microscopic examination. During microscopic examination, all kinds of nematode eggs are generally not easy to distinguish, except for the hairy first nematode eggs, fine-necked nematode eggs, Yangkou nematode eggs, Marshall nematode eggs and other characteristics, other kinds of nematode eggs are not easy to distinguish. In addition, the control methods of various nematode diseases are basically the same, and it is generally not necessary to identify the types of eggs, as long as a large number of eggs are found in the fecal examination, more than 1 000 eggs per gram of feces of sheep should be dewormed.

Lambs containing 2,000 to 6,000 eggs per gram of feces are considered to be severely infected. Postmortem autopsy diagnosis can be found in the corresponding intestinal segment for identification, which can distinguish which nematodes cause the disease.

The sheep carcass is emaciated, anemia, there are different numbers of nematode parasites in various parts of the digestive tract, catarrhal enteritis, and small yellow dotted nodules and purulent nodules can be seen in the large intestine. Edema of the true gastric mucosa, sometimes traces of insect bites and small nodules with needle tips as large as miliary are seen, and the liver and spleen are atrophied to varying degrees. The systemic lesions of the sick sheep are mainly anemia and edema, the mucous membrane and ** are pale, the blood is thin like water, and the internal organs are pale in color.

There is pleural effusion, pericardial effusion, and ascites, and the fatty tissue in the abdominal cavity becomes jelly-like. The liver may have a pale brown color due to steatosis. The lesions on autopsy are mainly manifested in the lungs, and there are different degrees of lung distension and emphysema, the surface of the lungs is bulging, grayish-white, and there is a feeling of hardness when touched; There are viscous or purulent secretory masses mixed with blood streaks in the bronchi; Large and small lung nematodes can be found in the trachea, bronchi, and bronchioles.

The main manifestations of various sheep digestive tract nematodes are digestive disorders, inflammation of the gastrointestinal tract, diarrhea and emaciation; The conjunctiva of the eye is pale, the growth and development are stunted, and the seriously ill sheep can die due to extreme physical failure. Necropsy showed varying numbers of corresponding nematode parasites in various parts of the digestive tract. and variable degrees of gastroenteritis changes.

The prenatal diagnosis of the disease is usually done on a fecal ova test in clinically suspicious sheep. The method of microscopic examination of eggs is carried out by saturated saline floatation method, and the method is to take about 10 grams of suspected diseased sheep feces and add a small amount of saturated brine first (dissolve the table salt in the water, and stir while adding salt until the salt in the water can no longer be dissolved). And stir to make the feces miscible in saline, filter and pour into a small penicillin bottle, fill the vial, and cover the slide, so that the slide is in contact with the liquid level of the bottle mouth.

Let it stand for 30 minutes, remove the slide, cover the coverslip at the place where the slide touches the liquid surface, and examine it under a microscope to find a large number of eggs. The stool can also be directly diluted with water and smeared to examine the eggs. As long as a large number of eggs are found in the fecal examination, that is, 1000 eggs per gram of sheep feces, deworming should be carried out, and lambs containing 2000 6000 eggs per gram of feces are considered to be re-infestation.

Postmortem autopsy can distinguish which nematode infection is by finding worms in the digestive tract.

There are 10 main species of nematodes that parasitize the digestive tract of sheep:

Spear elegans twist: parasitic in the true stomach and occasionally in the small intestine.

Osteritals: parasitic on the true stomach.

Marshall nematode: parasitic on the true stomach.

Trichostrongyloides: parasitic in the small intestine.

Fine-necked nematode: parasitic in the small intestine or true stomach.

Cooper nematode: parasitic in the small intestine, pancreas, and occasionally in the true stomach.

Nematodes: Parasitic in the small intestine.

Esophageal orifice nematode: parasitic in the large intestine.

Charbert's nematode: parasitic in the large intestine.

Trichocephalus: parasitic in the cecum.

The above nematodes are often mixed to infect sheep, causing harm to sheep in different procedures. It is one of the important causes of sheep mortality in the spring deficiency season every year. The disease occurs and is prevalent to varying degrees in all parts of the country, especially in the pastoral areas of Northwest, Inner Mongolia and Northeast China, which brings serious losses to the sheep industry.