Veterinary Services

Generalised and systemic conditions

Lameness and eight or nine sudden deaths were reported in 14-week-old pigs. The batch morbidity was approximately 20 per cent. Postmortem examination showed polyarthritis, acute exudative pneumonia and meningitis associated with Streptococcus suis serotype 2 in affected pigs.

Circulatory conditions

Two outbreaks of mulberry heart disease were diagnosed in unrelated units. Both involved multiple deaths in batches of eight-week-old pigs over a course of two to three days. The pigs were either found dead, or recumbent and died a very short time later. The gross pathological findings were typical of the condition (figure 3) and acute degenerative cardiomyopathy was confirmed by histopathological examination.

Alimentary tract conditions

Viral-type enteropathies were diagnosed in seven to eight-week-old pigs on two units where the pigs had originated from the same breeding herd. Diarrhoea and ill thrift were reported, with the pigs losing condition rapidly. The small intestinal contents were watery and mucoid. On histopathology there was loss of epithelium from a number of the villus tips, early inflammatory cell infiltration and atrophic changes to villi. Rotavirus testing of the three pigs was negative and the cause remained unknown.

Spirochaetal colitis was diagnosed postmortem in pigs from five unrelated units. The age groups ranging from seven to thirteen weeks.  The gross and histopathological changes were typical of the condition. Salmonella Typhimurium DT120 was detected as a co-infection in two instances.

In a separate incident there was evidence of spirochaetal colitis, viral-type enteropathy and proliferative enteropathy in seven-week-old pigs that were failing to thrive. Salmonella Reading was also isolated in enriched cultures from the intestinal contents from the two pigs submitted.

An attaching coliform infection and early stage spirochaetal colitis were diagnosed on histopathology in a batch of seven-week-old pigs. They were scouring and failing to thrive. There was a high morbidity and a few deaths. Two out of the three pigs submitted had widespread coliform attachment to the surface epithelium of the small intestine and also more limited areas of the large intestine. Moderate numbers of large spirochaetes were present in many colonic crypts. Another batch of eight to nine-week-old pigs on a different unit but which originated from the same breeding unit as the previous case also had signs of ill thrift and diarrhoea. Both submitted pigs had acute enteritis associated with attaching coliform infection and an attaching/effacing process was suspected.

Ill thrift and diarrhoea were reported as affecting batches of pigs between 20 and 60 kg on one unit.  The affected batches totalled around 600 pigs. There was approximately 15 per cent morbidity and less than one per cent mortality.  Bacterial cultures and PCR testing revealed a hippurate negative strain of Brachyspira pilosicoli.  This variant was first recognised in Finland and is an unusual finding in the UK.

Swine dysentery was diagnosed in a batch of pigs that arrived on a unit two days previously. There were about 15 ill thriven pigs out of the batch of 200 and it was reported that one pig passed unclotted blood containing mucus. Brachyspira hyodysenteriae was confirmed by PCR. There was also a parasitic colitis associated with Trichuris species.  In a separate incident, swine dysentery was confirmed as the cause of ‘sudden death’ in seven nine-week-old pigs in a batch of 200. All three pigs had oedema of the ascending colon mesentery (figure 4) and mucohaemorrhagic colitis.

An outbreak of acute swine dysentery in sows on an unrelated unit was confirmed by postmortem examination.  Three sows died out of a group of 24. The sows developed a watery, yellow scour after weaning their litters. Gross and histopathological lesions affecting the colon were typical of swine dysentery. The source of infection was not determined.