Veterinary Services

Actinobacillus suis infection was diagnosed in three 18-day-old piglets submitted for necropsy from a breeding unit. A number of sudden deaths occurred in different litters and some scouring was noted. The necropsy findings suggested bacteraemia/septicaemia in each case, and bacterial cultures isolated A. suis from multiple organs, as well as two pathogenic strains of E.coli  (V165 and Abbotstown) from the intestines. Intestinal histopathology failed to demonstrate any evidence of enteric pathology or coliform attachment to the intestinal surface epithelium in the sections examined. Histology of other tissues showed acute inflammatory changes that supported the diagnosis of A.suis infection.

Two outbreaks of Streptococcus suis serotype 2 infection occurred on unrelated units. In the first instance, ten deaths occurred in a group of 300 seven-week-old pigs. Pigs had either been found dead or were exhibiting signs of inco-ordination. Necropsy changes included pulmonary congestion and fibrinous peritonitis and/or synovitis. Streptococcus suis serotype 2 was isolated from multiple organs of all cases. In the second instance, there were 16 deaths out of approximately 800 ten-week-old pigs. Necropsy examination showed generalised congestion, pulmonary oedema and meningitis, with isolation of Streptococcus suis serotype 2 from multiple organs, including the meninges.

Haemophilus parasuis plus Salmonella Typhimurium DT120 infection were diagnosed as the causes of death in two eight-week-old pigs in a batch of 400 weaners. The main clinical signs in the group were of yellow diarrhoea and weight loss. At postmortem examination both pigs were in poor body condition with fibrinous polyserositis and yellow exudate associated with the caecal and colonic mucosae.