(1) Pathogen

Fasciola hepatica parasitizes in the liver and bile ducts of sheep. Its appearance is like a willow leaf, so it is called willow leafworm or liver leech (Figure 10-1 ). The insect body is purple-red when fresh.

Figure 10-1 Sheep liver leech

The female parasitizes in the bile duct and lays eggs. The eggs enter the intestines with the bile and are finally excreted in the feces. The eggs hatch and develop into miracidia under suitable conditions, and the sheep become infected when they are swallowed. This disease mostly occurs in humid and watery areas, mainly in summer and autumn, and is often endemic.

(2) Symptoms

The most common symptoms are chronic, with edema in the eyelids, mandible, under the chest, under the abdomen and other parts of the body. The sick sheep are anemic and emaciated, and the coat is rough, dry and dull. , easy to break and fall off. Appetite decreases or disappears. Severe infection or poor feeding conditions can cause large numbers of deaths.

(3) Necropsy

The liver was enlarged, soft, and bleeding. When the cut surface was squeezed, yellow liquid flowed out and there were young worms of Fasciola hepatica.

(4) Treatment

① Carbon tetrachloride. Adult sheep use 1 to 2 ml at a time, and half-year-old sheep use 1 ml at a time. When taken orally, mix it with liquid paraffin (or rapeseed oil) at a ratio of 1:2 and put it in through a rubber tube. For intramuscular injection, mix equal amounts with liquid paraffin and inject into deep muscles of the neck or buttocks (Figure 10-2). If poisoning occurs, intravenously inject 10 calcium gluconate or 5 calcium chloride solution, or take calcium chloride solution orally. To detoxify.

Figure 10-2 Carbon tetrachloride injection site

② Nitrochlorophenol. The dosage of sheep per kilogram of body weight is 3 to 5 grams, taken orally once.

③Thiobisdichlorophenol. The dosage is 0.1 g per kilogram of body weight. This medicine is insoluble in water and can be dissolved in alcohol and taken orally.

④Althiobendazole. 10 to 20 mg per kilogram of body weight, taken orally once.

(5) Prevention

①Regular deworming and elimination of eggs is the basic measure to eradicate this disease. Deworming is done twice a year. The first time is from March to April, and the second time is in October. After deworming, they should be moved to a dry and snail-free area to allow the eggs to be laid in fixed pastures, and then transferred to other pastures to reduce pollution.

② Eliminate the intermediate host. Use copper sulfate at a concentration of 1:5000 to 10,000 to kill the snails.

③Sodium chlorophenol concentration is 1:10000, killing snails.

④ Clear channels and improve drainage systems. Improve the soil and fill in low-lying areas, making it impossible for snails to survive.