Veterinary Services

The month was dominated by diagnoses of meningitis and septicaemia in weaner pigs in Aberdeenshire, Invernesshire and Lothians.

Septic arthritis, septicaemia and meningitis due to infection with Streptococcus suis serotype 2 were confirmed in four unrelated units in 6 to 9-week-old pigs. One was a grower unit that had recently been re-populated after a six-month empty period. Twenty-four piglets from the first batch of 400 showed nervous signs at six to seven-weeks-old. The worst affected ones were in lateral recumbency and paddling. Fibrinous pericarditis was also a feature of the necropsies.

Acute suppurative meningitis was diagnosed in an eight-week-old Hampshire-cross pig in a ‘minimal disease’ unit that is considered to be free from Streptococcus suis serotype 2 infection. It had received antibiotic treatment 24 hours prior to submission and bacterial cultures of the meninges were sterile. In view of the negative culture result the cause could not be confirmed but this case has lead to concerns about the health status of the herd.

Proliferative haemorrhagic enteropathy was confirmed in an organic herd that reported several grower pigs off their legs with no apparent loss of condition. Large numbers of intracellular organisms consistent with Lawsonia intracellularis were observed in sections of colon with the use of special stains.

Several deaths were noted in one of four pens of weaners that had arrived on an outdoor finishing unit a week previously. Postmortem examination confirmed gastric ulceration as the cause of death.

Four faecal samples were submitted from scouring lactating sows in an outdoor unit. All were positive for Trichostrongylid-type eggs consistent with Oesophagostomum spp. Three of the four had high counts (100, 3,200, 2,900 and 2,800epg). No bacterial enteropathogens were detected so the parasites were considered to be the cause of the diarrhoea described.

Torsion of the large intestine around the root of the mesentery with subsequent perforation was confirmed in a gilt due to farrow in four weeks. The gilt was noted to be off food for 24 hours and died shortly after being found in extremis.

Three 12-week-old pigs were submitted from a unit where wasting and pneumonia occurred four to five weeks after weaning. There were also some cases of arthritis. All three of the pigs had a very severe fibrinous pleuropneumonia. The lungs were grey to dark red in colour and consolidated. Nearly all of the lung tissue was involved in each case. There were widespread adhesions to the thoracic wall and in two of the pigs there was a thick layer of fibrin covering the lung serosa. One animal had a massive fibrinous pericarditis. All three had excess peritoneal fluid and some fibrin clots. Actinobacillus pleuropneumoniae serotype 3 and Pasteurella multocida type A were isolated from the lungs lesions of two of the pigs. There was evidence of underlying PMWS on histopathology. PMWS is likely to have exacerbated the respiratory condition.

Three 12-day-old piglets were submitted from a unit experiencing losses from a number of litters at the 7 - 14 day stage. The piglets were undersized and thin but bright and alert with no evidence of recent scour or other significant clinical signs. On postmortem examination the piglets were found to have very sparse gut contents with no evidence of enteritis or other significant gross lesion. On subsequent histopathology all three piglets showed extensive hepatocellular vacuolation consistent with hypoglycaemia but no evidence of inflammatory or degenerative changes in the intestines or any other tissues. Malnutrition was suspected and advice was given on investigation of potential maternal and management factors. Further investigation for possible infectious causes was also advised.