How to deal with the surveillance results in the background investigation stage of pseudorabies in p

Biosecurity is a measure to prevent the introduction of infectious diseases into the farm, within the farm and out of the farm. Some of them are critical, such as the safety of introduction, the management of pig loading stations, the disinfection of pig trucks, rodent extermination, mosquito and fly control, the control of dogs and cats, the control of foreign personnel, etc., and the ultimate goal is to strictly prevent pseudo-rabies virus, especially the introduction of new strains. Regardless of whether the pig farm is positive or negative, it is necessary to introduce pseudorabies and wild virus negative breeding pigs, first of all, to understand the pseudorabies status of the breeding pig farm, and then need to be tested one by one, and it is best to eliminate GE antibody positive pigs.

Quarantine during the isolation period needs to be carefully observed and regularly tested, if there are GE antibodies turned positive, they need to be resolutely eliminated. Pig loading table management The pig loading table is the gateway to the outside world to the pig farm production area, from which many diseases are introduced to the pig farm, so it needs to take a one-way flow, and the pigs that come out cannot be returned. After loading the pigs, they need to be thoroughly rinsed and disinfected, and the sewage cannot be backflowed.

Transport vehicles transport vehicles need to be rinsed, disinfected and dried in all directions, as he is the most polluted, especially for vehicles going to the slaughterhouse. <>

Immunity is a measure to increase herd-specific resistance, i.e. to eliminate susceptible animals. Pseudorabies virus (belonging to the herpesviridae family), even if it contains neutralizing antibodies in the body, cannot completely prevent and eliminate wild virus invasion and infection, but can prevent the onset of disease, reduce the amount of toxin and shorten the time of detoxification. The selection of vaccines must be matched with gene deletion vaccines, such as vaccines with TK and GE deletions, but too many deletions are not conducive to the colonization of vaccine viruses and the formation of immunity (that is, the more gene missing, the better).

The mutant pseudorabies strain can still cause morbidity in many pig farms that have been immunized with the classic pseudorabies vaccine, and the mutant pseudorabies virus genetically modified vaccine has a good effect on the pseudorabies caused by mutant PRV infection, and is convenient for differential diagnosis with the clinical infection strain, but the cross-protection between different strains ** vaccines is not accurate, so it is necessary to make a differential diagnosis of the clinical pseudorabies infection strain before selecting the vaccine strain. Although some strains have a good match for the immunogenicity of antigens, their immunogenicity varies greatly due to the different degrees of passage or the different deletion genes. <>

1.Clinical symptoms.

1) the initial redness of the eye sockets, closed eyes and lethargy, and then the body temperature rose to 41, depressed, there is a lot of foam or saliva at the corners of the mouth, some sick pigs vomit or diarrhea, the contents are yellow, the initial stage is mainly neurological disorders, and the later stage is characterized by paralysis. The most common are intermittent convulsions, seizures, angular reflexion, blind walking or turning in circles, and immobility. Almost 100% of piglets with neurological symptoms die, and the onset piglets tend to be stunted or stiff after tolerance.

2) Piglets over 20 days old to weaning piglets with mild symptoms, body temperature rise to more than 41, shortness of breath, scattered coat, no food or reduced appetite, purple ear tips, morbidity and mortality are lower than 15 days of age piglets.

3) Pigs about 4 months old, only mild symptoms after the onset of the disease, a few days of mild fever, dyspnea, runny nose, cough, depression, loss of appetite, some in a "dog sitting" posture, sometimes vomiting and diarrhea.

4) Sows sometimes have anorexia, constipation, tremor, convulsions, loss of vision or conjunctivitis, some delivery is delayed or early, some give birth to stillbirths, mummified fetuses or abortions, the piglets born are small and weak, and the weak fetus dies after 2 3 days, and the incidence of abortion is about 50%.

2.Prevention and cure. 1)** There is no specific drug for this disease, and the infected pigs can be injected with porcine pseudorabies high immunity serum, which has obvious effects on weaned piglets, and the application of astragalus polysaccharide traditional Chinese medicine preparations**. Emergency immunization is carried out against threatened pigs that do not develop the disease.

2) prevention of the disease should be mainly based on prevention, the introduction of new pigs to carry out strict quarantine, after the introduction of isolation observation, blood testing, the detection of positive pigs to inject vaccines, not for breeding. Breeding pigs should be regularly vaccinated with inactivated seedlings, fattening pigs or weaned pigs should also be immunized with live seedlings or inactivated seedlings at the age of 2 to 4 months, if only immunized breeding pigs, fattening pigs can be excreted after being infected with the virus, which directly threatens the breeding pig herd. Pig farms should be disinfected regularly and strictly, preferably with a 2% sodium hydroxide (caustic soda) solution or a phenolic disinfectant.

Strict rodent extermination should be carried out in pig farms to eliminate the danger of rodent poison-borne diseases.

1. Symptoms of pseudo-mad limb inulnard dog disease.

Once the pig is infected with pseudorabies virus, the ** rate is very low, and the sick pig often dies within a few days, and there will be some obvious neurological symptoms, such as vomiting, trembling, high chirping, limb stroke, in addition to fever, diarrhea, poor mental state, do not like to eat and other symptoms. Sows infected with pseudorabies virus will have symptoms of repeated infertility, miscarriage and stillbirth.

Second, self-breeding and self-raising, all in and all out.

In recent years, farmers have generally understood the importance of self-farrowing, which can largely avoid diseases on the farm. Foreign vehicles and personnel should also be disinfected and biosecurity measures should be taken. Dogs, cats, birds, rats, and other animals are strictly forbidden to enter the farm to eliminate possible vectors, especially rodents.

3. Conduct timely inspections and strengthen monitoring.

When the pig farm introduces foreign pigs, it should do a good job of testing and vaccination, and isolate it for at least half a month before mixed group feeding. In the process of feeding, maintain a more reasonable feeding density, regularly inspect the reproductive performance of the pig herd, and once there is a reproductive problem, it should be eliminated.

Pseudorabies virus infection is generally uncharacteristic. Visually, the kidneys are mainly pinpoint-shaped hemorrhage, and other gross lesions are not obvious. Catarrhal gastritis and enteritis of different degrees of distinction width can be seen, and the central nervous system can be seen.

When the symptoms are obvious, the meninges are obviously congested, the cerebrospinal fluid is excessive, and gray-white necrotic foci are often seen in the liver, spleen and other solid organs, and pulmonary congestion, edema and necrotic points are often seen. Intrauterine infection can progress to lytic necrotizing placenta.

The histological lesions are mainly diffuse non-purulent meningoencephalitis and gangliitis of the central nervous system, with obvious vascular cuffs and diffuse local glial cell necrosis. In the internal branches of cranial nerve cells, nasopharyngeal mucosa, spleen, and lymph nodes.

Intranuclear eosinophils and hemorrhagic inflammation are seen in lymphocytes. Coagulative necrosis around the lobules of the liver is sometimes seen. Alveolar septal nucleus lobular widening, lymphocytes, monocytes. Infiltration.