Rotaviruses in Piglets

What are rotaviruses in pigs?

Rotaviruses are non-enveloped RNA viruses; in pigs, Group A is of primary clinical importance, although Groups B and C also occur. They replicate in the mature, absorptive enterocytes of the small intestinal villi and, by causing villus atrophy, lead to a reduced absorptive surface area and malabsorptive diarrhea.

Rotaviruses are ubiquitous; nearly every adult pig has experienced a rotavirus infection and developed corresponding antibodies. They are among the most important pathogens in young animals, are not highly host-specific, and remain infectious for a long time both in the environment and within pig barns. After oral ingestion, the viruses invade the intestinal cells (enterocytes) and destroy their absorptive function. Isolated rotavirus infections often proceed subclinically, without affecting the animal’s general condition. These subclinical carriers represent a source of infection for other animals.

The “2-Week Diarrhea” in Suckling Piglets

The so-called “2-week diarrhea” in piglets occurs between the 10th and 21st day of life. It is characterized by low feed intake, occasional vomiting, and mild diarrhea. Rapid spread of the infection occurs, with a morbidity rate (incidence) of 100% and a mortality rate (death rate) of 50%. This clinical course usually occurs in piglets as antibody levels in sow’s milk decline during the second to third week of life.

Risk Factors and Mixed Infections

However, in cases of mixed infections with other diarrhea-causing pathogens, worm infestations, pre-existing underlying conditions, poor barn hygiene, and insufficient colostrum intake by the piglets, diarrhea episodes with severe diarrhea, significant losses due to mortality, and stunted growth may occur. Therefore, motherless rearing is particularly problematic.

Transmission in the Barn

Transmission occurs via the fecal-oral route; the viruses remain infectious in the barn environment and the outside world for an extended period. Clinically asymptomatic adult animals shed the virus, thereby maintaining the infection pressure within the herd. Rotaviruses are among the most common viral causes of diarrhea in piglet rearing; the peak of the disease typically occurs around the second to third week of life, when the level of maternal antibodies in sow’s milk declines.

Diagnosis of Rotaviruses

It is not possible to determine the etiology based solely on the clinical presentation, as the clinical courses of the various diarrhea-causing agents overlap and mixed infections are common. Antigen detection in fresh feces from several affected animals narrows down the range of potential pathogens and supports targeted therapeutic, hygiene, and herd management measures.

Rapid Tests for Piglet Diarrhea

The Fassisi® PiDia and Fassisi® PiDia light tests detect rotavirus antigen in the feces of young animals (piglets, lambs, calves). PiDia also detects Clostridium perfringens and Cryptosporidium parvum, while PiDia Light detects rotavirus and Clostridium perfringens; this allows for the differentiation of single and mixed infections from a single sample.

The technical details are documented on the sources page.