Veterinary Services

Generalised and systemic conditions

Further cases of Streptococcus suis serotype 2 meningitis were diagnosed on a holding in three- and five-month-old pigs. The older pigs  were coughing. S.suis serotype 2 was isolated from the lungs and brains and there was gross evidence of meningitis. The pigs came off tiamulin medication two weeks previously.

Eight- to twelve-week-old pigs from another finishing unit, under the same ownership as previous cases of S.suis, were submitted to investigate the cause of a sudden death and a case of lateral recumbency. S.suis serotype 2 was isolated from the brain of the case of sudden death and from the brain, liver and lung of the other pig.

Five tonsillar swabs from boars were cultured to check for Streptococcus suis. An untypeable S.suis was isolated from three of the five pigs.

Alimentary tract disorders

Acute clostridial enteritis was diagnosed in three-day-old pigs from an outdoor unit reporting a long term scour problem with deaths in very young piglets. There was a necrotic yellow diphtheritic membrane over the small intestinal mucosa and congestion of the serosal blood vessels. Clostridium perfringens was isolated from the ileum. Histopathology confirmed widespread necrotising enteritis associated with invasion of the mucosa by large numbers of clostridial type bacteria.

Clostridium perfringens type A enteritis was also diagnosed in two-day-old piglets submitted from a breeding unit in Perthshire. There was a history of scouring and death amongst outdoor born piglets. Litters of gilts seemed most affected with some litters recording around 50 per cent mortality. At necropsy the bodily condition was poor and there was some evidence of recent scouring.  A section of the duodenum was haemorrhagic with fibrin strands present over the serosa and mucosal necrosis. Distal to this the small intestine was distended by blood-tinged fluid contents.  A short section of the spiral colon also showed acute congestion. Bacterial culture of the intestinal mucosa and contents yielded heavy growths of Clostridium perfringens. The gut contents were positive for the presence of clostridial alpha toxin.

Two six-month-old gilts died suddenly having arrived on an outdoor unit ten days previously. They were part of a batch of 50. Both pigs had a necrotic, diphtheritic enteritis affecting part of the small intestine and the affected loops were adherent. Growths of Salmonella Reading were isolated in culture from the intestinal contents of both pigs. One gilt also had a more generalised peritonitis, dry pleuritis and adhesive pericarditis. Profuse growths of Clostridium sordellii were isolated in systemic cultures from the autolytic carcases.

Proliferative enteropathy was diagnosed by histopathology in two three-week-old pigs with a history of enteritis.  One presented with mucosal necrosis, while the other showed widespread haemorrhages and capillary distension typical of proliferative haemorrhagic enteropathy (PHE).  Silver-stained sections showed numerous intracytoplasmic bacteria consistent with Lawsonia intracellularis, with particularly high numbers in the pig with the PHE lesions.