Duck parasitic helminthiasis-duck subclonorchiasis

Duck clonorchis is a parasite that lives in the bile duct or gallbladder of duck liver. It mainly harms ducks over one month old, and the infection rate and infection intensity are very high. Death is often caused by blockage of gallbladder and bile duct worms, which is a great harm to ducks at present. There are two kinds of Clonorchis sinensis parasitic in the gallbladder and bile duct of ducks (Clonorchis orientalis and Clonorchis Formosa). The most common in clinic is Clonorchis orientalis.

1. Pathogen and epidemic characteristics the pathogen is Clonorchis orientalis, which belongs to the family epididymidae. The insect body is leaf-shaped, 2.4-4.7 mm long, with small spines on the body surface, the oral sucker is located in the front end of the insect body, and the ventral sucker is located in the center of the front 1 of the insect body. The testicles are large, slightly lobulated and arranged back and forth at the back end of the body. The front of the testis is an oval ovary, and the uterus is coiled between the ovary and the intestinal fork. The uterus is full of eggs, which are light yellow and oval in size, with a size of 28 × 31 μ m × 12 × 15 μ m. The disease often occurs in summer and autumn. Clinically, ducks aged from 1 to 4 months are more common, while ducks under one month of age rarely occur. The parasite is parasitic not only on ducks but also on chickens, occasionally in cats, dogs and humans. The disease is widely distributed and has been reported all over the country.

two。 The first intermediate host in life history is striped marsh snail, and the second intermediate host is wheat spike and crawling tiger fish. Metacercariae are mainly parasitic in the muscle and cortex of fish. The duck was infected by swallowing fish containing metacercariae, and the eggs appeared in the feces 16-21 days after infection.

3. When the clinical symptoms were mild infection, there were no clinical symptoms; in severe infection, the sick ducks suffered from mental fatigue, loss of appetite, loose feathers, weakness of both limbs, emaciation and anemia, frequent dysentery, watery feces, and mostly died of failure. The laying rate of laying ducks decreased after infection, but if the disease was serious, the laying stopped and died.

4. The pathological changes of the liver were significantly enlarged, some of which were 1-2 times larger than the normal, and the color became lighter, showing white patterns and spots of common bile duct hyperplasia. When the course of the disease is slightly longer, the texture of the liver hardens, the wall of the bile duct thickens, the lumen expands, and the coagulants and worms containing yellowish-green bile can be seen on the section. The gallbladder is full, the bile is dark green or dark green, there are different numbers of worms in the cystic cavity, the gallbladder wall is thickened, and the intestinal mucosa shows catarrhal inflammation. A few cases also had pericardial effusion, splenomegaly and cecal tonsillar hemorrhage.

5. Prevention and control measures to strengthen environmental hygiene, cleaning and disinfection of duck houses, accumulation and fermentation of cleared duck manure for biological heat treatment, do not feed ducks with raw fish. In addition, the prevention and treatment of diseased ducks with drugs one by one, such as albendazole 50 mg / kg body weight 100 mg, or praziquantel oral 10 mg / kg body weight 15 mg, have a good effect.