Sexually transmitted diseases. The main clinical manifestations were septic changes, hemorrhage of parenchymal organs and infarction.
Classical swine fever virus belongs to the genus flaviviridae pestivirus. At present, it is believed that classical swine fever virus has only one blood.
Clear type, but virulence is divided into strong, medium and weak. Classical swine fever virus (CSFV) is a single-stranded RNA with virus particles.
Spherical, with a diameter of 38 ~ 44 nm. The virus is distributed in various tissues of sick pigs.
The content in lymph nodes, spleen and blood is the highest, and the lowest infection is millions of pigs per gram. Sick pig
There are a lot of viruses in all kinds of urine, feces and secretions, and the virus content is the highest when you have a fever.
Classical swine fever virus (CSFV) is not heat-tolerant, and 7CC can make the virus lose infectivity after 1 hour.
Under dry conditions, the virus is easy to die, and the polluted environment is in dry and direct sunlight.
Under this condition,/kloc-0 can lose infectivity after 4 weeks. Alkaline disinfectants such as caustic soda and quicklime.
We can kill the virus quickly.
(1) diagnostic points
1. Epidemiological characteristics: The disease only infects pigs. Pigs of different breeds, ages and sexes can be used.
The infection started. Sick pigs and infected pigs are the main sources of infection, and pigs are infected with virus 1 ~ 2 days.
Can detoxify the outside world; After 5 ~ 6 weeks of recovery, sick pigs can still carry poison and detoxify; The excrement of sick pigs
Materials, secretions, blood, meat, internal organs, waste and waste water in the slaughter process all contain a large number of diseases.
Poison. The virus spreads directly or indirectly through feed, drinking water, utensils, articles, people and the environment.
Contact transmission, generally through digestive tract infection, but also through respiratory tract, conjunctiva, damaged skin or castration.
Wound infection during cutting. The virus can infect the fetus vertically through the placenta, resulting in weak children, stillbirth,
Mummies, etc. Insensitive animals and people may be the mechanical spreaders of viruses. The disease lasted for a year.
It can happen all year round.
2. The incubation period of main symptoms is generally 5 ~ 7 days, and the shortest is 2 days. According to the duration of the disease
The clinical symptoms can be divided into the most acute, acute, subacute, chronic and mild types.
Wait a minute.
The most acute type (1) is more common in the early stage of the epidemic, mainly characterized by sudden onset and high fever.
Body temperature can reach 4 1. C Vg_b_, cyanosis bleeding point of skin and visible mucosa, whole body.
Spasms, limb convulsions and rapid death.
(2) Acute type is the most common, and the body temperature rises to 4 1 ~ 42. C, depression, action
Slow movement, drowsiness, trembling, hunchback, loss of appetite or reduction. Conjunctiva is red, how much is the corner of the eye?
Measure purulent secretions and even make eyelids adhere. The oral mucosa is cyanotic with bleeding spots. male pig
Urine accumulated in the foreskin can squeeze out turbid and smelly urine. Constipation at the initial stage of the disease, spherical secretion with blood.
With the development of the disease course, diarrhea and constipation appear alternately. Initial skin
The first stage is flushing and congestion, followed by bleeding spots and spots on the inside of ears, neck, abdomen and limbs.
Hypothermia before death.
(3) The symptoms of subacute type are similar to those of acute type, but mild, and the course of disease is usually 3-4 years.
Zhou. Immortals often become chronic.
(4) Chronic clinical manifestations are emaciation, weakness, high and low body temperature, loss of appetite,
Constipation and diarrhea appear alternately, with dull fur and weakness in walking. Some sick pigs are at the ear end and the tail tip.
And the skin of limbs has purple spots or necrotic scabs. Sick pigs often die in the end, but they don't grow up when they die.
Stages are stunted and become stiff pigs.
(5) Pregnant pigs with reproductive disorders do not show clinical symptoms after infection, but the infection time is longer.
And it can be transmitted to the fetus through the placenta, leading to pregnancy abortion' target =' _ blank'> pig abortion, premature birth, stillbirth or mummy.
Fetal pigs, weak pigs or new pigs are born with shivering heads and limbs and usually die a few days later.
(6) Mild symptoms are mild and atypical, including ear skin, tail and limbs.
At that time, there was necrosis, the development of sick pigs was stagnant, quadriplegia could not stand in the later stage, and some sick pigs had tarsal bones.
The joints are swollen.