Differential Diagnosis Methods and Prevention and Control Measures for Reproductive Disorders in Sows (1)
Differential Diagnosis and Prevention and Control Measures for Reproductive Disorder Diseases in Sows (1)
The main diseases causing reproductive disorders in sows include porcine parvovirus disease, porcine epidemic encephalitis B, porcine pseudorabies, porcine blue ear disease (porcine reproductive and respiratory syndrome), swine fever, porcine leptospirosis, porcine toxoplasmosis and brucellosis, etc.
1 Differential diagnosis based on epidemiological characteristics
1.1 Epidemic season
Porcine epidemic encephalitis B has obvious seasonality, that is, it occurs more frequently in summer and autumn when mosquitoes are active; the epidemic season of leptospirosis is mainly in the high-temperature season from July to October; porcine pseudorabies mostly occurs in spring and winter; the other several diseases have no obvious seasonality and can occur in all four seasons.
1.2 Age of onset
Susceptibility to brucellosis and parvovirus disease increases with sexual maturity; leptospirosis mostly affects young animals; toxoplasmosis mainly affects pigs aged 3 to 4 months, while the other four diseases are susceptible at different ages. However, the clinical manifestations of porcine blue ear disease and porcine pseudorabies show obvious age differences.
1.3 Route of transmission
Porcine parvovirus disease is transmitted through contact with contaminated sources, the placenta and semen; porcine encephalitis B is mainly transmitted through mosquito bites; porcine pseudorabies is mainly transmitted through the respiratory tract, digestive tract and damaged skin; porcine blue ear disease is transmitted through direct contact; swine fever is transmitted through the respiratory tract (tonsils) or direct contact; porcine leptospirosis is mainly transmitted through the skin, mucous membranes and digestive tract, and can also be transmitted through mating, artificial insemination or through blood-sucking insects during the bacteremia phase; porcine brucellosis is transmitted through the digestive tract, skin wounds and mating.
2 Differentiation based on clinical symptoms
Affected sows all show common symptoms such as repeated infertility, abortion or the birth of stillborn fetuses and mummified fetuses, and weak newborn piglets. In addition to the above symptoms, sows with porcine parvovirus disease show no other symptoms, and most other pigs are also asymptomatic; pigs with encephalitis B mostly show neurological symptoms, persistent high fever, and individual cases of mild hindlimb paralysis; newborn piglets with porcine pseudorabies show relatively severe symptoms, including high fever, difficulty breathing, incoordination of the limbs, circling, vomiting and diarrhea; if neurological symptoms appear in the early stage of onset, the mortality rate can reach 100%, while young pigs show milder symptoms and a lower mortality rate;
low; piglets with porcine blue ear disease show rapid abdominal breathing or panting, with a mortality rate of 80% to 100%; in epidemic areas, a large number of piglets die after weaning, and young pigs mainly show respiratory symptoms; after infection with porcine leptospirosis, most pigs show inapparent infection with no obvious clinical symptoms, and a few show an acute course with short-term fever, anemia and jaundice, etc.; porcine toxoplasmosis occurs mostly in pigs aged 3 to 4 months, manifesting as high fever and difficulty breathing, with piglets showing watery diarrhea and recovering if they do not die within half a month, while adult pigs show an inapparent course; swine fever, porcine blue ear disease and porcine toxoplasmosis all involve bleeding and purpling of the skin on the ears, the edges of the ear flaps, the underside of the abdomen and the inner sides of the legs; porcine parvovirus disease, porcine pseudorabies, porcine blue ear disease, brucellosis and toxoplasmosis present as asymptomatic abortion and stillbirth in sows; porcine encephalitis B, swine fever and porcine leptospirosis present in sows as symptomatic abortion and stillbirth accompanied by fever and other symptoms.