Porcine pseudorabies

The disease is an acute infectious disease of pigs and other animals caused by pseudorabies virus. It is characterized by fever, itching (except pigs) and symptoms of encephalomyelitis. Adult pigs often have recessive infection, with abortion, stillbirth and respiratory symptoms, while suckling piglets generally show neurological symptoms.

Pathogen:

The pathogen is herpesviridae, herpesvirus type I. The virus has strong resistance, but it is sensitive to heat, formaldehyde, ether and ultraviolet rays. There is only one serotype of this virus.

Epidemiology:

The disease can occur in all seasons of the year, but it often occurs in winter and spring and the peak season of giving birth. The disease often occurs first in sow houses at the peak of delivery, almost in every litter, with an incidence of 100%. However, morbidity and death had a peak, and then gradually decreased. Diseased pigs, poisoned pigs and poisonous rodents are the important sources of infection of the disease. The virus is excreted from nasal secretions, saliva, milk and urine, and susceptible pigs are transmitted mainly through direct and indirect contact. The disease can be infected through digestive tract, respiratory tract, skin, mucous membrane and reproductive tract, as well as vertical transmission. The infection of lactating sows can be transmitted to suckling piglets through milk.

Clinical symptoms:

The incubation period of the disease is usually 3-6 days. The diseased piglets showed neurological symptoms, agitation, muscle spasm on the body surface, nystagmus, upward flipping, and dyskinesia. There are intermittent convulsions, severe angular arch dilatation, fever, high fever, and finally coma and death. The course of the disease was 36ml for 48 hours. Tolerant piglets tend to be stunted and become stiff pigs. Most of the sows were transient and subclinical, and pregnant pigs had abortion and stillbirth. The incidence of miscarriage is 50%.

Pathological changes:

The changes with diagnostic value were catarrhal or suppurative hemorrhagic inflammation of the nasal cavity, tonsillar edema accompanied by pharyngitis and laryngeal edema, serous infiltration of spoon-shaped cartilage and epiglottic wrinkle wall, and often covered by fibrous necrotic pseudomembrane. Pulmonary edema, upper respiratory tract contains a large number of foam-like edema, laryngeal mucosa and serosa can see punctate or macular bleeding. The lymph nodes, especially the mesenteric lymph nodes and mandibular lymph nodes, were congested, enlarged and bleeding. Endocardial hemorrhage, renal punctate hemorrhagic inflammatory changes, large area hemorrhage at the bottom of stomach, small intestinal mucosal hemorrhage, edema, mucosal wrinkle wall, large intestine plaque hemorrhage, meningeal congestion, edema, cerebral parenchyma punctate hemorrhage, longer course of disease, pericardial fluid, pleural and peritoneal fluid, cerebrospinal fluid increased significantly, and there was a large amount of cellulose exudation on the surface of the liver.

Diagnostics:

A preliminary diagnosis can be made according to clinical symptoms and epidemiology, and pathological diagnosis or laboratory diagnosis is necessary to diagnose the disease.

Vaccine can be used to prevent the disease. In order to eradicate the disease completely, it is necessary to quarantine repeatedly and eliminate positive pigs. In addition, disinfection and rodent control should be done to prevent the spread of disease.