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