Veterinary Services

Generalised and systemic conditions

Two 12-day-old piglets were submitted to investigate the cause of skin lesions where there were areas of either no hair or areas of purple discolouration. One piglet had multiple areas of hairless skin affecting the left carpus, both elbows, the left metacarpophalangeal joint, the sternum, chin and coronary band. The histopathological findings suggested congenital hypotrichosis. The second piglet had multiple purple blotches and streaks, predominantly over the trunk, especially the ventral abdomen and sternum. There were subcapsular petechiae on the kidneys. Haematology provided evidence of anaemia, leukopaenia and an absence of platelets. The packed cell volume (PCV) was 0.19 l/l (reference range 0.37 to 0.46 l/l), the total red cell count (RBC) was 2.3x10^12/l (reference range 6.5 to 8.0x10^12/l and the total white cell count (WBC) was less than 1.0x10^9/l (reference range 10.0 to 23.0x10^9/l). These findings were consistent with a diagnosis of thrombocytopaenic purpura.

A three-week-old gilt with a history of lack of co-ordination was presented. It was unable to stand and adopted a dog sitting position. It was pyrexic with swellings of the hock and stifle joints. Streptococcus suis serotype 1/14 was isolated from the joints, liver and brain.

Streptococcus suis serotype 1/14 was also isolated in septicaemic distribution and from the brains of two four-week-old pigs from a holding where six sudden deaths had occurred in pre-weaned pigs in good body condition. Acute degenerative cardiac changes consistent with vitamin E deficiency were also identified in both pigs.

A six-week-old gilt was submitted as part of an investigation into the poorer performance of a nursery unit compared to other units under the same ownership. There were two massive liver ruptures and a large volume of free blood in the abdomen, suspected to be due to terminal trauma. There was a severe wet fibrinous pleurisy affecting both lungs and also a fibrinous pericarditis. The lungs were hyperaemic with interlobular and interstitial oedema. A moderate mixed bacterial growth was isolated from the lung. This was predominantly an untypeable Streptococcus suis plus a scant growth of Haemophilus parasuis. Histopathology confirmed exudative pneumonia and pleurisy suggestive of Glasser’s disease.

The cause of nine deaths in one shed on a finishing unit was investigated. An ill thriven pig from the unit was euthanased. It had septic polyarthritis and fibrinous pericarditis from which Streptococcus suis serotype 2 was isolated.

Alimentary tract disorders

Scour and ill thrift were reported in a single batch of 12-week-old pigs on a finishing unit. The two pigs submitted had evidence of a typhlocolopathy. In both cases the caecum and colon were distended with green liquid contents and there were prominent lymphoid aggregates visible on the serosal surface of the large intestine. Yersinia enterocolitica was isolated in culture from one pig but histopathology showed colitis associated with significant numbers of large, fine spirochaetes consistent with a spirochaetal colitis.

Porcine intestinal adenomatosis was diagnosed in a batch of four-month-old boars with presenting signs of diarrhoea and loss of condition. Three of four pigs submitted for postmortem examination had the regional ileitis form and evidence of necrotic enteritis. PCR confirmed the suspicions that Lawsonia intracellularis was responsible.

A five-month-old finishing boar was euthanased when it was found staggering and scouring. Porcine intestinal adenomatosis was suspected. At postmortem examination the mucosa of the ileum appeared slightly congested and oedematous but the large intestinal contents were firm. The kidneys were enlarged with small circular pale foci with central dark areas on the external surfaces. The renal cortices showed streaking on cross-section. Histopathology showed renal lesions consistent with porcine dermatitis and nephropathy syndrome and exudative lymphadenitis in the renal lymph nodes.

Skin diseases

A skin scraping sample was submitted from an adult boar on a breeding unit in Perthshire. The pig had recently entered the unit and showed pruritic, malodourous seborrhoea. Ectoparasitism was suspected. Microscopic examination of the material found no evidence of ectoparasites. Bacterial cultures yielded growth of Staphylococcus chromogenes. Although a normal commensal of pig skin, Staphylococcus chromogenes has been implicated in cases of porcine exudative epidermitis where there was no evidence of infection with Staphylococcus hyicus.