Veterinary Services

Six weaned piglets showing nervous signs were noted in an outdoor unit, with no previous history of meningitis. A dull, five kg pig was submitted.  It did not exhibit nervous signs but had a tendency to sternal or lateral recumbency. A septic arthritis affected the right and left stifle and carpal joints and an excess of turbid synovial fluid was present in all joints. A purulent exudate underlay the meninges in the region of the cerebellum and brainstem. Streptococcus suis serotype 1/14 was cultured from the spinal cord, left elbow, stifle joints and the brain.

Two eight-week-old Tamworth piglets from an outdoor unit became ill and died within 24 hours. The postmortem findings in both pigs were extensive anteroventral pneumonia and generalised congestion of tissues. Arcanobacterium pyogenes was isolated from the lungs and multiple other tissues of both cases, and histopathology showed semi-purulent meningitis and widespread neutrophil infiltration in lung, liver and spleen consistent with an acute systemic bacterial infection. Acute systemic bacterial infection most likely associated with A. pyogenes was diagnosed in both piglets.

Glasser’s disease was diagnosed on postmortem examination of a 19 Kg weaner pig in a batch of 50. Breathing difficulties were seen the previous evening and it died overnight.  The pig was in good bodily condition with marked, thick “bread and butter” peritonitis, pleuritis and pericarditis.  There was no gross evidence of meningitis, arthritis or other significant pathology.  Haemophilus parasuis was isolated from the pericardium.

Sudden deaths in 20 of 600 pigs during one week stimulated a classical swine fever (CSF) alert on account of numerous haemorrhages in carcase tissues, multiple organs, mucosal and serosal surfaces, in one pig submitted for postmortem examination. Both kidneys were pale and enlarged with many petechial haemorrhages in the cortices. An early pericardial reaction was evident, with a 'stickiness' present. Veterinary officers of Animal Health ruled out CSF on clinical inspection of the herd. Streptococcal septicaemia was diagnosed on further investigation.

A three-year-old sow in a small unit in Caithness died suddenly after farrowing.  At post mortem examination the heart was found to be pale and enlarged.  Histopathology showed widespread acute degenerative cardiomyopathy. The farm is in an area where selenium deficiency in ruminants is common.

Alimentary tract disorders

Four faecal samples were submitted from a breeding herd that was experiencing scour problems in neonatal piglets. Escherichia coli, which was polyB positive, was isolated in culture and rotavirus type C was detected in three of the four samples.

One of 70 seven-week-old pigs was found dead without prodromal signs. Postmortem examination and histology findings were consistent with bacterial enteritis and colitis associated with profuse growths of Salmonella Typhimurium  [phage type 193] and E coli were obtained from the colon. Histopathological examination of lymph nodes showed early lymphocyte depletion and atrophy of lymphoid follicles.  This suggested that early or subclinical PMWS contributed to the clinical problem.

Two finisher pigs were submitted from a farm with a history of chronic vomiting in occasional animals.  The pigs weighed 73.5 Kg (male) and 70.5 Kg (female).  They were both in fair to good bodily condition with no external evidence of diarrhoea.  Examination of the stomach revealed extensive scar tissue formation and fibrosis consistent with healed ulcers around the cardiac sphincter.  The lumen of the sphincter was reduced to three to four mm leading to almost complete obstruction.  The oesophagus was slightly dilated and contained food material.  The caudal third was markedly thickened, hypertrophied and firm.  No other gross abnormalities were detected.  Postmortem examination of three smaller pigs (45.5 Kg, 57.5 Kg and 64.5 Kg) pig from the same farm 12 weeks previously had revealed gastric ulceration in all with extensive involvement of the cardiac sphincter in two. Dietary factors were discussed.

Salmonella screening was carried out on a herd to investigate a high seroprevalence at slaughter. Salmonella Typhimurium phage type 193 was isolated from a maiden gilt and from four piglets. Incoming gilts may therefore have been the source of infection for the young stock.