Duck viral hepatitis dvh) is known as "dorsal neck disease". It is a highly pathogenic infectious disease in which the main duck opens the inflammation I poison dhv) causes liver damage in the vivo duck. Pro does not present as a dyskinesia. After death, the inner horn bow is reversed. It is characterized by open organ enlargement and bleeding.
Identify pathogens
Duck hepatitis virus (DHV). present. Duck open inflammation virus can be divided into 1 according to serotype. 1. Severe, no cross-infection between 3 blood elimination types. Serum type 1 can be divided into 3 genotypes. They are genotype 1 (traditional serum type 1), genotype 1 (Taiwan type), genotype subtype (Korean type). The main epidemic in China is the traditional DHV 1 type and its new Korean variant strain ndhvd. Well has been reported as a pandemic. In 2010, south Korea's new DHV was first discovered at night in Fujian Province, China.
Know the law 1
(1) Sick ducks and poisonous ducks of infectious origin. Recovered Vickers can be detoxified in 1 to 2 months with stools.
(2) The transmission route is mainly transmitted through the respiratory tract and digestive tract.
(3) Popular characteristics Can occur all year round, to winter. Spring is more common.
(4) Susceptible animals mainly occur in victorian ducks under 3 weeks of age. In particular, it is extremely lethal to 1-week-old ducks, and the case fatality rate is as high as 90%. In recent years, ducks around the age of 30 have also developed diseases.
(5) Latest developments At present, the new type of hepatitis that occurs (type I duck viral hepatitis is distributed worldwide, type II is only found in the east of England, and type II mainly occurs in the United States) does not belong to these three serotypes, but belongs to other serotypes, so it is called new hepatitis. Its clinical symptoms are similar to those of type 1 duck viral hepatitis, but the two are significantly different in tissue lesions, mainly the new duck hepatitis virus can lead to obvious lesions of kidneys and elastic organs, severe kidney necrosis and heterophilic fine infiltration, and dirty red camps. The boundaries of the white questions change significantly.
[Look at the symptoms]
(1) The incubation period is 1 to 2 days, and the onset of the disease is sudden. Mental bondage, neck and wings, outliers, eyes half-closed, often chickens, sleep well, appetite, conjunctivitis.
(2) Spasmodic fingers, head back, bent vigorously to the back, feet back extended, severe spasm. Looking swimming, with an angled arch in an inverted posture, he dies within minutes to hours.
(3) The beak end and claw tip are dark purple, and a few sick ducks die in yellow-white or green thin feces.
(4) Sudden death with a more acute onset, often see no symptoms.
[Lesions]
(1) The liver is enlarged, brittle, cracked when touched, the color is dull or earthy yellow, yellowish white, brownish yellow, the surface is scattered with bleeding spots of different sizes, reddish or mottled, and the cut liver can be seen to be valgus, juicy, and the structure is blurred.
(2) The gallbladder is obviously enlarged, and the bile is full of star dark green.
(3) Pericardial effusion, myocardial color becomes pale and soft, cooked, ventricular dilation.
(4) The spleen is soft and swollen, the surface is red and white mottled, and the cut surface is turned outward and juicy.
(5) Pancreas is enlarged, congested or bleeding, pink, and some have small white lesions on the surface.
(6) The kidney swelling is gray and dark, the blood vessels are obvious, and the dark purple dendritic "spot kidney" is present. (7) The bursa is large, and the blood vessels on the surface of the brain are obviously easy to see, bruised, and dilated like dendritic branches.