Diseases

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Rotavirus enteritis

Rotaviral enteritis is a common disease of the small intestine in pigs. Rotaviruses are present on most farms. All pigs are susceptible, but enteritis leading to significant diarrhea is usually seen in newborn and post-weaning pigs. There are seven antigenic types of rotavirus, four of which have been identified in pigs. Group A corresponds to the classic rotavirus and is the most common. The virus destroys the epithelial cells of the villi of the small intestine, causing serious villous atrophy, malabsorption, osmotic diarrhea and dehydration.

Clinical Signs +

In its neonatal epidemic form, the disease resembles transmissible gastroenteritis, but it is less severe. If neonatal pigs do not receive sufficient levels of protective maternal antibodies, they are likely to develop profuse watery diarrhea in 12 to 48 hours. The diarrhea often begins in pigs aged five days to three weeks or immediately after weaning. The feces of nursing pigs are often yellow or gray and pasty in the early stages and progress to gray and pasty in less than two days. Diarrhea persists for two to five days. Infected piglets become gaunt. Weaned pigs have watery feces that contain poorly digested feed.

Diagnosis +

Etiological diagnosis is difficult and rotaviruses are difficult to isolate. Immunohistological diagnosis will show the virus in intestinal cells, but with this diagnostic method, observations must be recorded from the onset of diarrhea because results become negative if the diarrhea persists for several days. Immunoenzymatic tests detecting the A antigen are useful. Serological diagnosis is of no benefit because rotaviruses are present on most farms.

Treatment +

There is no specific treatment. Treatment is symptomatic and consists in limiting dehydration. Your veterinarian is the best person to talk to for recommendations that are right for your farm.

Prevention +

Active infection of the intestine by rotavirus creates a natural protective immunity. Because rotavirus is easily spread during an epidemic by people, animals and objects, special care must be taken to prevent it from spreading to unexposed groups of pigs and neighbouring farms. A vaccine combined with E. coli is available. It is administered to pregnant sows and gilts before they have farrowed. Piglets acquire passive protection from the colostrum.

REFERENCES:

1 Merck Veterinary Manual, Third Edition

2 Maladies d’élevage des porcs (Hog Farming Diseases), 2nd Edition, Guy Pierre Martineau