Liver fluke disease is a highly prevalent animal disease, and the degree of pollution and harm it produces is not the same. The seasonality of the disease is more pronounced, with the highest incidence during the rainy seasons that alternate between spring and summer. In this paper, the epidemiology of bovine and sheep liver tablets trematodiasis is analyzed, and its diagnostic symptoms and diagnostic and treatment techniques are analyzed, in order to provide a reference for the prevention and control of bovine and sheep liver flukes.
Ruminants such as cattle and sheep are more susceptible to parasitic diseases, of which liver flukes are more common, and trematodes are the main pathogens, mainly including liver flukes and large flukes. Suffering from this disease can cause acute and chronic hepatitis, cholangitis, and even cause animal poisoning, resulting in serious nutritional disorders.
I. Epidemiology
Liver flukes are a multi-epidemic parasitic disease in China, and the harm of this disease varies in different regions and periods, and the pollution situation is inconsistent. During the rainy season, it is more susceptible to this disease, the rain will wash the insects in the feces of poultry into the water insects, the snails will multiply in large quantities when the water level is high, and the large-scale spread will cause cattle and sheep to be infected with parasitic diseases. Therefore, the incidence of liver flukes in humid and low-lying areas is high, and the rainy seasons of spring and summer are suitable for the reproduction and spread of snails, which is conducive to the growth, development and hatching of liver fluke eggs.
2. Diagnose symptoms
When cattle and sheep are mildly infected with this disease, the clinical symptoms are not obvious, and if there is a large-scale infection, the typical symptoms of onset will occur. When the larvae of cattle and sheep are infected with liver fluke disease, they will cause extremely serious damage to it. Sheep are infected with acute liver fluke disease, usually in late summer and early autumn, due to the sheep eating a large number of cysts in a short period of time, the larvae will move in the liver of the sheep and cause their disease. After the onset of the disease, the sheep will have obvious mental malaise, abnormal body temperature, decreased appetite and accompanied by diarrhea symptoms. In the diagnosis of the liver, its semi-dull area is significantly enlarged and more sensitive, after which there are obvious symptoms of anemia and the mucous membrane is white. Cattle and sheep die after three to five days of illness. Chronic liver flukes are more common, caused by adult trematode parasitism in the bile ducts of cattle and sheep. After the infection of sheep with this disease, there will be obvious symptoms of anemia, whitening of the mucous membranes, and edema of the eyelids and lower parts of the chest and abdomen. The back hair of the sick sheep is scattered and loses luster, showing obvious dryness. Some sick sheep will have hair removal, digestion will also be affected, and the peristalsis of the rumen will decrease, which will cause enteritis. After the disease, cattle and sheep will have symptoms of decreased appetite, significant weight loss, and then severe failure and death.
3. Pathological autopsy
During the pathological autopsy, it can be found that the liver of cattle and sheep will undergo obvious pathological changes, and the number of infections and the time of onset vary in the degree of change. Analysis of acute and large-scale infections reveals acute hepatitis, significant hepatomegaly and bleeding symptoms, a 2 to 5 mm cord in the liver, dark red, soft texture, squeezing the section will flow out of the cloudy yellow mucus, which contains juvenile insect bodies, obvious blood-colored fluid in the abdominal cavity, and peritonitis lesions. Cattle and sheep with chronic liver fluke disease will suffer from chronic proliferative hepatitis, their liver tissue will be destroyed, and gray-white axillary cords will appear, the liver of the sick animal will be significantly atrophied, the color will become lighter and the texture is harder, the edges are blunt and round, there is obvious interlobular connective tissue hyperplasia, the thickness of the bile duct will increase significantly, the phenomenon of expansion will occur, and the liver surface will be prominent. The inner wall of the bile duct is rough and firm, with a viscous bloody fluid inside that contains insect bodies, accompanied by black-brown or yellow-brown phosphate stones, in a granular or lumpy distribution.
Fourth, the main points of diagnosis and treatment
1. Diagnostic points
Comprehensive diagnosis should be made in combination with the symptoms of the diseased cattle and sheep, the epidemiological data of liver fluke trematodiasis, and the egg examination should be carried out, and the pathological autopsy results should be used as the basis for diagnosis of this disease.
2. Prevention and control points
(1) Therapeutic measures
In the treatment process of liver fluke disease, it is first necessary to deworm, take effective treatment measures according to specific symptoms, and timely treat cattle and sheep with serious diseases or weak physiques. Deworming can be performed by means of drugs.
There are many commonly used types of deworming drugs, such as the use of nitrochlorophenol for deworming, the dosage per kilogram of cattle is 5-8mg, the dosage of sheep is appropriately reduced, 4-6mg is appropriate, and one-time oral administration can be. Coriban drugs have obvious killing effects on adults and larvae, scalpers per kilogram of 75-100 mg, sheep dosage of 80-120 mg, a one-time oral dose can be.
(2) Preventive measures
Combined with the epidemiological characteristics of bovine and sheep liver flukes, the developmental history of bovine and sheep is understood and comprehensive prevention is carried out. The first task is to deworm, and the specific time and frequency of deworming are determined according to the prevalence of the disease in the area. In the northern region, it is necessary to carry out secondary deworming every year, and once in late autumn and early winter to avoid the disease in winter, and a second deworming can be carried out in early spring to reduce the spread of pathogens by reducing out-of-the-field grazing. Secondly, it is necessary to rationally treat the manure of cattle and sheep. Timely cleaning of the breeding house, centralized fermentation of feces, and timely killing of insect eggs. After the completion of the deworming, it is also necessary to use a pollution-free way to treat cattle and sheep feces to avoid the spread of germs. Third, make a reasonable choice of grazing land. Higher grasslands are selected for grazing to avoid infection with liver trematodiasis. If grazing is necessary for low-lying, wet and other pastures suitable for trematode survival, a phased grazing plan should be developed. Grazing time here in the summer is up to two months, and other pastures are selected for grazing. Finally, it is also necessary to strictly carry out breeding management and use full-price feeds to ensure adequate nutrients. At the same time, it is necessary to provide clean drinking water for cattle and sheep to avoid water source pollution by insects, so as to reduce the incidence of chinococcosis in cattle and sheep.
About author:Xiaohua Li Assistant Veterinarian