Rotovirus

 

Causal agent

Virus – Rotovirus Double stranded RNA non  enveloped

Type A most common, but many strains.  Also 5 types A-E are known in pigs.

Age group

Clinical signs normally between 7 and 14 days of age. 

Clinical signs unusual over 28 days of age

Clinical signs

No colostral immunity

Severe clinical signs in young pigs below 14 days of age.

Severe profuse diarrhoea.  Diarrhoea watery, yellow, white with flecks of tissue.

Diarrhoea continues 3-5 days and mortality may reach 100%

Colostral immunity

No clinical signs or a mild diarrhoea.

May contribute to other causes of diarrhoea – E. coli for example

scour k1

PB200097

Watery and yellow diarrhoea

Diarrhoea may also contain vomit

Infectivity

 

The virus is extremely resistant to temperature, chemicals and disinfectant, pH changes.

The virus will survive 3 months or more in the environment.

Transmission

 

The virus is ubiquitous (everywhere). 

Transmission is by the oral-faecal route.

Sows may excrete the virus at the time of farrowing


 

Post-mortem Lesions

 

Very watery diarrhoea and dilated small intestines

The small intestinal villi will be shorter – up to 1/10 length of normal

pH of the intestinal contents acidic (E. coli normally alkaline)

Note recovery of intestine may occur within 72 hours so postmortem findings more severe in acute case.

 

Rotovirus normal  jejunum

 

 

 

 

Rotovirus atrophy jejunum spb

 

     Normal small intestine villi

Shortened villi with Rotovirus

Diagnosis

 

Difficult as the organism is common and antibodies are normal

Histological examination of the intestine in acute cases

Treatment

Sick pigs

Supportive treatment with electrolytes

Preventative

Feedback

Essential to ensure that the gilt is provided with experience of the farm’s Rotovirus population so she can pass this immunity on to her piglets

 

Feedback to sows 6-4 weeks pre-farrowing during outbreak

Colostrum

Review colostrum availability- especially fostering protocols

Hygiene

All-in/all-out and good hygiene between groups will help reduce clinical signs

Vaccine

Available in some countries but many not be effective due to the number of different strains

Common differentials

 

TGE and EPD.

Play a common role in other piglet diarrhoea’s – E. coli and Coccidiosis

Zoonotic

 

Rotovirus is a common virus of Man, but direct transmission not demonstrated.