This virus is widespread in pig populations. It is present in most if not all pig herds with virtually a 100% sero-conversion in adult stock. A further epidemiological feature is its persistence outside the pig where it is resistant to environmental changes and many disinfectants. Maternal antibodies persist for 3-6 weeks after which pigs become susceptible to infection but exposure does not necessarily result in disease. It is estimated that only 10-15% of diarrhoeas in pigs are initiated by a primary rotavirus infection. In a mature herd disease appears after piglets are 7 to 10 days of age. It becomes progressively less important with age. However if pathogenic strains of E. coli are present severe disease can occur with heavy mortality.
Symptoms
Sows
- Transient diarrhoea.
Piglets
- Watery profuse diarrhoea in younger animals.
- Villus atrophy is a consistent feature with dehydration, malabsorption and wasting.
- Diarrhoea usually persists for 3-4 days.
- Pigs look hollow in the abdomen and become dehydrated.
- The eyes are sunken.
- The skin around the rectum is wet.
Weaners & Growers
In a mature herd:
- A watery profuse diarrhoea appears after piglets are 7 to 10 days of age. It becomes progressively less important with age.
- However if pathogenic strains of E. coli are present severe disease can occur with heavy mortality.
- Villus atrophy is a consistent feature which results in malabsorption.
- Dehydration.
- Diarrhoea usually lasts 3-4 days.
- Pigs look hollow.
- Eyes are sunken.
- Skin around the rectum is wet.
The role of rotaviruses in the post-weaned pig is probably less important although they are often identified when acute E. coli diarrhoea occurs in the first 7-10 days after weaning.
Causes / Contributing factors
- Poor house hygiene.
- Permanently populated houses. Adopt all-in, all-out.
- Movement of pigs.
- Temperature fluctuations.
- Contaminated boots and clothing.
Diagnosis
Whenever there is a diarrhoea problem in pigs between 10 and 40 days of age rotavirus infection either as primary agents or secondary must be considered. Electron microscopy and ELISA tests in the laboratory are required for confirmation. Try the litmus test by soaking scour in litmus paper, E. coli infections turn blue, virus infections red.