What are the symptoms of African swine fever in sows?

SummaryFirst day: body temperature around 38.5°C, decreased appetite. Second day: body temperature rises above 40°C, unable to stand, trembling all over, ear tips turn red-purple, belly turns red, feces relatively dry. Third day: body temperature around 40°C, red rings around the eyes, belly color darkens, the entire ear turns gray-purple, rump turns red-purple, feces contain blood. Fourth day: death will occur. Sow about to farrow: the farrowing date will be delayed, abnormal during delivery, constantly rubbing the vulva.

Symptoms of African swine fever infection

1. Sows

Generally, infection in most cases starts with sows. On the first day of onset, the sow's body temperature is 38.5°C, spirits are relatively good, appetite is relatively poor. By the second day, the sow's body temperature rises to 41.5°C, unable to stand, trembling all over, ear tips turn red-purple, belly turns red, feces relatively dry. On the third day the sow's body temperature is around 40°C, red rings around the eyes, belly color darkens, the entire ear turns gray-purple, rump turns red-purple, feces contain blood, in the shape of an abacus bead; on the fourth day death occurs.

Sows pregnant for less than three months will all abort; sows pregnant for more than three months refuse food initially, and later abort as well. In addition, a few will vomit yellow fluid, with body temperature between 41.5-42°C, dry feces, and discoloration of the ears, belly and hindquarters; as soon as the body temperature drops, death follows immediately. Generally death occurs about 4 days after onset, or about 8 days in slower cases, and at death they are all in a prone position.

Sows about to farrow will have their farrowing date delayed by about 2-3 days, and will behave abnormally during delivery, constantly rubbing the vulva, leading to massive hemorrhage and death; a very few die after successfully delivering piglets, and some die only on the fourth day after farrowing.

Sows have relatively low immunity more than half a month after farrowing, and generally develop the disease after weaning; in those not yet weaned, the onset is merely delayed. According to clinical data, if a sow has not been weaned and has not developed the disease by about 43 days after farrowing, about 1-2 piglets will die.

Sows pregnant for more than 3 months have a relatively late onset, relatively good spirits, eat little food, and after about 4-5 days their bodies will turn red-purple.

2. Finishing pigs

In the early stage of onset, finishing pigs begin to huddle together, with body temperature between 41.5-42°C, somewhat similar to flu symptoms; a few pant, and on the second day huddling is more obvious; a fever-reducing injection provides some relief, ear tips turn outward, the body turns red, appetite is still fairly good.

On the third day they huddle less, dense bleeding spots appear on the body, redness is severe, appetite is still fair, the whole body trembles; after injection treatment, the injection site bleeds continuously, the belly becomes sunken, the ears turn purple, the rump turns red, and there may also be blood in the urine and black feces. For persistent high fever, using isatis root and bupleurum is more effective.

3. Nursery pigs

The symptoms of onset are not very obvious: the whole body is pale, the belly is yellow-tinged with purple patches, the manifestations of sick pigs differ somewhat, and at death most ears do not change color, with the whole body going limp.