Veterinary Services

Generalised and systemic conditions

An indoor unit with a relatively new farrowing house reported problems with poorly viable piglets at birth. There were no mummified piglets but the newborn piglets were reported to be very thin. The problem started at the end of September, waned but then recurred a few weeks later. Multiple litters across different parities were affected and up to 50 per cent of the litter was affected. Postmortem examinations on four piglets showed evidence of neonatal bacterial infections. Pure growths of Klebsiella pneumoniae were isolated in culture from the livers of two piglets from different litters, and a profuse, mixed growth of predominantly Aeromonas hydrophila, was isolated from the liver of another piglet. As the piglets were undernourished at birth it was advised that placentas should be submitted for further investigation. SAC C VS recommended that the quality of the straw for the dry sows should be checked and the possibility of mycotoxin involvement could not be ruled out.

 
Three outbreaks of meningitis associated with Streptococcus suis serotype 2 infections were diagnosed in finishing pigs on unrelated units. The ages of pigs affected were 15-week-old on one unit and 20 week-old on the other two. The mortality rates within affected batches were two per cent, five per cent and six per cent respectively. The batch of 180, 15-week-old pigs arrived on the unit three weeks previously. They were receiving in-feed penicillin medication as a preventative measure, as cases of Streptococcus suis type 2 meningitis occurred in the previous batch of pigs delivered from the source farm. The medication appeared to reduce the prevalence of cases but did not prevent the problem entirely. The mortality rates of five and six per cent in 20-week-old pigs constituted a significant economic loss and at that age, presented practical problems as regards medication and adherence to withdrawal times before slaughter.

Alimentary Tract Conditions

Rotavirus type A was diagnosed as the cause of watery diarrhoea which started at 21 days of age in multiple litters of piglets.  The infection was having a negative impact on weaning weights.
Outbreaks of swine dysentery due to Brachyspira hyodysenteriae were diagnosed in three finishing units. One outbreak had co-infection with Brachyspira pilosicoli, and another co-infection with Salmonella Reading and Yersinia pseudotuberculosis. B. pilosicoli was the sole pathogen isolated from two outbreaks of diarrhoea in ten to 12-week-old growing pigs on unrelated units.