Veterinary Services

Generalised systemic diseases

A case of porcine dermatitis and nephropathy syndrome (PDNS) in Ayrshire stimulated a classical swine fever alert on account of the gross post mortem findings of multiple petechiae in the kidneys, peripheral lymph nodes and bronchial tree. The five-month-old landrace x large white pig was euthanased after developing bloody diarrhoea, weakness on its legs and respiratory signs. Two other pigs in the herd of 40 had died in the previous week. Samples collected by the State Veterinary Service were tested for swine fever with negative results. Histopathology subsequently demonstrated diffuse chronic glomerulonephritis and vasculitis affecting multiple tissues including the intestinal mucosa, consistent with a diagnosis of PDNS. Haemorrhagic skin lesions were absent in this particular case.

An outbreak of polyserositis, pneumonia and rhinitis among weaners on one unit yielded Haemophilus parasuis and/or Streptococcus suis serotype 7 from affected tissues. The piglets were in good bodily condition but had shown dullness, lethargy, sneezing and coughing for 24 hours. As this unit is enzootic pneumonia-free, piglets were euthanased for diagnostic purposes. It appears that the two agents were co-pathogens in this outbreak.

Streptococcus suis serotype 14 was diagnosed as the cause of septic polyarthritis in weaners derived from two supply farms. Mortality was low but there was significant morbidity among the group of 190 weaners.

Respiratory tract disease

A breakdown of enzootic pneumonia was confirmed in six-week-old piglets that were showing coughing and ill-thrift. The unit had been repopulated in May 2005. The source of infection was unclear.

Alimentary tract disorders

Two 25-day-old piglets were euthanased and submitted from a unit suffering from acute diarrhoea and deaths in the pre-weaning period. The mucosae of the stomach, small and large intestine were congested with widespread petechiae, and the gut contents and faeces were fluid in nature. Histopathology showed acute haemorrhagic necrotizing enteritis in both piglets. Analysis of intestinal contents for Clostridial toxins by ELISA confirmed the presence of both alpha and beta toxins consistent with the presence of Clostridium perfingens type C. The diagnosis of Clostridial-type enteritis is unusual in piglets of this age as this condition is generally confined to piglets less than 14 days old.

Outbreaks of diarrhoea in growing and finishing pigs on several units were associated with either Brachyspira hyodysenteriae or Brachyspira pilosicoli solely, or either of these agents in combination with Lawsonia intracellularis and/or Salmonella enterica Typhimurium.

Parasitic disease

Four faeces samples from diarrhoeic adult sows were all positive for Oesophagostomum dentatum eggs. The counts from the sows from one unit were 1,100 and 3,200 epg and from the other 200 and 900 epg. O. dentatum is a recognised cause of colitis and diarrhoea in pigs.